Without knowing what software, or even operating system/platform you're using, it's hard to be specific. However, nearly any program which lets you save as as jpeg, will probably also offer some options, including one for something like jpeg quality. Reducing the quality from 100 to 85-90 percent will typically reduce the size of the file by at least a third, maybe almost half, and you'll have trouble seeing the difference. Depending on the photo, you can sometimes go lower.
You may also have options to scale the image, so that it displays at a smaller size than the original (this is nice, since we don't have to scroll horizontally to read all of the following posts...).
Mica had some helpful suggestions recently, see the post dated Nov. 17, in Factory to Customer/Randy's Custom Clarke Deluxe. Having just reviewed that, reducing resolution to 72dpi is pretty obviously the first step (hey, she does this all the time, and I don't even have a digital camera yet).
You probably want to stick with jpeg, rather than gif, since gifs are limited to 256 colors. Reducing resolution, quality, and/or scaling should all help to get things down to a reasonable size. Just try saving a couple different ways, and look at the sizes of the files on your disk (and how the images look on screen).
