jpg compression is a compromise between file size and picture quality - presumably your camera uses a very high quality setting for the compression - or they are huge!! My camera takes pictures that are 1800x1200 and the resulting jpg files are in the order of 3-400Kb. I resize them to about 800x550 (or there about) as lots of people have screens that only show a resolution of 800x600, though they still look good on larger screens. The file size is then about 50-90Kb.
Compression programs such as WinZip or WinRar will have a minimal effect on the files, as jpg is already a compressed format - though at 2Mb a picture the compression may be minimal and you may get somewhere!! Jpg's usually compress about 2% (A saving of only 30Kb on my 300Kb files). If your file does compress well it may be that you get a 20% reduction, which would still leave you with a 1.6Mb file...
Resizing is the better option though, there is little point in the picture being bigger than the screen (especially if emailing). Save the resized version as a new file rather than overwrite the original if you want to keep a higher quality "original".
There are free graphics programs as mentioned earlier, I find the GIMP to be very powerful, and this has been included on cover disks and is available for download.
Phil Hull
October 2003