The quickest way ive found to resize pics:

Open Microsoft paint - (start/programs/accessories/paint)
open the pic you want to resize.
go to image and choose stretch/skew
the top two fields will be 100 and 100% by default, you can change overall size by lowering number to 70 70 or 50 50 etc.
save pic as, then check size.
alot of times just resaving the pic in .jpg (if its not already) will reduce the size to under 100k

also cropping to take some of the pic out that you dont need works well to reduce size