For what it's worth I used to use the Snipping Tool, a lot!
Now I have switched to TechSmith's Snagit 10 because I can save captures as jpeg, png, bmp, ico, etc., plus it has a separate editing window to go back and customize the captures later.
It runs in either the 32 bit or 64 bit Windows 7 OS.
It's a "pay" program but it is so much more useful and has tons of features including highlight, arrows, text balloon insertion, text fields, etc.
They offer a free 30 day trial so you can install it and see how you like it. Plus there's tutorials on their website.
You can read more about here:
http://www.techsmith.com/screen-capture.asp