Is there an easy way to take any picture of any size and just shrink it down to 500K?I am bored of trying to guess which ____ X ____ will be enough to go under 500K.  Is there a trick I am missing? 

free program called shrink pic

http://www.onthegosoft.com/shrink_pic.htm

u can set it up to run automaticly when u email if you like

Andrew, the largest standard sixe 4:3 aspect ratio picture under 500K is 800 x 600, which works out at 480K pixels. Hope that helps

http://www.microsoft.com/windowsxp/using/digitalphotography/learnmore/tips/eschelman2.mspx

FREE!!

Yup, most "shrink 'em" softwares have a quality slider, which should tell you in real time what the file size will be.

Pixel dimensions and aspect ratio DO NOT determine file size, because fine details (e.g. leaves, a rough surface) require greater file size while less details (e.g. blue sky, placid body of water) require less.

Nearly all photo management software has an export to email function. Better to use this type of program because your original photos are kept as digital negatives and cannot be overwritten.

Try Picasa from google, it's free and as good if not better than most packages around the $100 mark.. Simple and intuitive.

http://picasa.google.com/index.html