I use a free screen capture program called greenshot (getgreenshot.org)

I hold Shift+PrintScreen, a cursor pops up, I highlight the area of the screen I want to capture and "Save As" a file to my desktop.

I always use the name "Capture.png" for my file, so every new screenshot replaces the last one, so no old, useless files pile up.

File size is typically less than 100k

Then I upload the pic to tinypic

Fast,easy and free.