EDIT: Argh, I've just realised after writing all that... there is actually a simpler way, which will get your stuff online and reduced fit for viewing... it's a little slow and painstaking for 25 files, but it works more or less in one click. (But after writing all that stuff I may as well leave it, as it will stand you in good stead for a multitude of other situations besides this.)
EASY METHOD
Take your massive file. Go to http://imageshack.us. Click Browse and choose the file. Go through the options below and find one that's something like "reduce size for messageboards (640x480)". Click that and hit Upload / Submit. Wait a moment whilst it chugs away sending your file (which will take a noticable time for 2mb even on a relatively quick ADSL, as sending is much slower than receiving these days), converting and redisplaying it. Copy the address of "direct link to file" into notepad (and hit Enter for a new line). Wash, rinse, repeat for the other 24 (click the frog at top left to return to the front page). Send the contents of the notepad file to your buddy and also save it to your HD. Job done. They can now download your reduced pictures right from imageshack, and either transfer them to the original site, or just provide links to the existing files. If you do this on a regular basis, you can also get a free membership (they'll probably start charging at some point..) so you can upload multiple files all at once and go grab some lunch while it whirrs away.
Ain't the internet grand?
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OK the original post follows. Batten down the hatches, as it's a Moby size one.
At that file size, I'm guessing they were taken with a 4 or 5 megapixel camera? They'll be FAR too big for online display or other general internet use. You'll need to reduce both the "physical" (pixel) size of the image, and the compression quality.
1/ The number of pixels in the image has a drastic effect on it's size. e.g. your camera has, say, 4 million pixels, with an image size of roughly 2250x1750. The screen I'm using to write this with on my laptop is 0.75 million pixels (1024x768), and a considerable wedge of that is taken up by task, tool, title, status, menu and scroll bars, and page margins. The available website picture display size on such a monitor is something around 960x600, and if you're using a messageboard or typical hosting site, this will be more like 800x600 or even lower, e.g. 720x540, 640x480 (or for MSN spaces, locked to 600x450). I shouldn't need to go into much more detail about how much this will cut the picture size even without changing the compression setting... 800x600 = roughly 0.5mp, or 8x smaller - i.e. each file will drop to about 250kb, a lot easier to handle, and ok even for 56k modem users, if they're moderately patient. (640x480 = 0.3mp, so ~150kb, and a little smaller for MSN Spaces)
2/ The compression level can also make quite an impact. JPG is what's known as a lossy format, similar to MP3 audio and MPG video. It works by filtering out complex, "unneccessary" data that the human eye "won't see" owing to various characterisics of our vision, chops it up into loads of little 8x8 pixel squares, and runs the result through a really quite simple compression engine (conceptually similar to Zip, which is why zipping the things won't do any good at all - the format was already designed for maximum crunch. if actual zip compression would have helped, it would already be part of the jpeg standard). The level of filtering, and the complexity and exact method of the final compression stage affect all three of the file size, apparent visual quality of the image reconstructed from the file, and the manner in which it loads over a slow connection.
Though the routine supposedly only chucks out image details that won't make any "real" difference to the image, this is not practically true, and high compression settings can really muck up the picture, to the point where the very highest ones are used more for artistic effect than useful image storage. The lowest ones aren't noticably different from the original except if you zoom waaaaaay in (slighly less well defined colours, etc) or run some analysis, but create ENORMOUS files. In between the two extremes there's a sweet spot that can be found, where the picture still looks quite good, whilst being efficiently small; and though it's different from the original, the changes are usually subtle enough (the odd wavy or squared-off border to an object, etc) that you can only tell by putting them side by side. On one side of this balance point size starts to improve ever more rapidly whilst quality doesn't improve much, and vice versa on the other (quality nosedives without saving much space). It's not worth hunting for it at length though, so long as you get close.
Digital cameras tend to err on the size of a better quality, large file in default mode, as you can always buy more memory cards or delete old pics, but you can't improve the quality of a dodgy JPG; hence for a 4mp camera with a 2mb file, you're only getting 6x compression (24bit colour = 3 bytes/pixel), less when you factor in the colour fidelity reduction that a jpg has regardless of the quality setting. Most will allow you to manually alter the compression setting (e.g. from "fine" to "normal" (near sweet spot) to "basic" (roughly just past it)) if you need a high number of pictures more than ultimate quality.
THEREFORE... the second thing you can do to bring the size down is to recompress them, more viciously than before. For showing onscreen, something equivalent to a camera's "normal" or even "basic" setting will be just fine... this is why most mobile phone camera images from a recent device look perfectly fine on a monitor, even if they're useless when printed out... they operate around 640x480 with a quality roughly equivalent to "basic".
To carry out both of these operations, you'll need some kind of half decent paint or photo editing program, and it's best to do it all in one go to avoid repeatedly compressing the image and losing more and more fidelity - load it, make the basic adjustments, and save it back out as a new file with stronger compression. Typically when uploading to MSN spaces i've been able to knock most files down to about 50kb, so they load wonderfully fast on broadband, and acceptably so on dial-up, without looking horrible. Obviously though, you'll need to keep the originals if you want to print them; 600x450 (about 100dpi on a standard size print) looks pretty awful on paper, but 1600x1200 (266dpi - 2mp camera) or higher will look brilliant.
One of the cool things about the photo editing program is that it will allow you to tweak other things first - e.g. crop out naff bits (especially important when reducing a detailed picture down to a much smaller onscreen size - don't waste a pixel!), sharpen the reduced picture (ditto), alter the brightness of a washed out or underexposed image (to a point), correct colour tints (e.g. incandescent lighting.. again, to a point), correct rotation, remove flash red-eyes, create panoramas and montages, so on and so forth. But for the purposes of this exercise, what it DOES need is a decent resize function.. MS Paint will NOT do for this purpose. Windows picture & fax viewer, plus printscreen to paste the result into paint, will just about do in a pinch. Better to use a proper program, of which you have a massive choice... if you can get it free, even better. Just do a websearch :)
What you need to be wary of is the jpg quality setting choices. Some won't allow you to alter this (e.g. ms paint). These programs need a slapping. Others will allow only a choice from a very small range of settings - e.g. 4 or 5, none of them too good. These aren't as bad, but might get a single, hard slap (backhand, with a sovereign ring). A professional grade JPEG engine, e.g. that in Paintshop pro (and probably in photoshop and the gimp) will give you a slider from 1 to 99 (in PSPs case, "very low" to "very high" COMPRESSION - in others, this may be QUALITY, i.e. the exact reverse), a choice of "standard" (more compatible) and "progressive" (slightly better compression with the same quality, nicer effect when loading on a slow connection) compression methods, and a preview pane to show how a selected part of the image will look at the current settings after reloading. Typically, in such a scheme, choosing Progressive with a compression of about 25 (1/4 the way down; quality level 75) will yield a satisfactory file size and appearance. If you think it's too messed up and can afford it to get larger, move it more towards 20 (or further for really complex images), and if it looks fantastic but is a little large, more towards 30 (again, further if it's pretty simple and isnt getting noticably corrupt). Anything lower than 8-10 or higher than 40-50 will either get too large for reasonable internet use, or start looking "over compressed".
Good luck and happy filesize chopping. See if you can get all of them into a single megabyte whilst still looking good (challenging, i'll admit :-D). You should quite realistically get all 25 inside the space of one of your current full-size ones for typical internet use (~82kb each - or 640x480 with slightly worse than doubled compression strength)