Cayman,
To resize, do the following....
Click:
Start, then
Programs, then
Accessories, then
Paint, (and then the MS Paint program will open up.)
After it's opened, Click:
File, then (drop down menu will appear)
Open File, (find the picture you want to resize)
Picture, then
Open, (the picture you selected will open in Paint)
Image, then (drop down will appear)
Stretch/Skew, then (pop up box will appear)
Enter 30 in the Horizontal box,
Enter 30 in the Vertical box,
click OK, (now the image should be smaller)
After it's resized, Click:
File, then (drop down menu will appear)
Save As, (Pop up window will open with the file name highlighted,
either use the same name or append it to reflect the smaller
size by naming it OriginalName Small.jpg or something along those
lines.
Now click Save.
Your picture should now be pretty close to 640x480,
you can re-upload it to your library. Keep in mind,
Libraries have a certain amount of space reserved for pictures,
so, the smaller they are, the less memory they take up.
Just make sure it is saved in the JPG format, not BMP.