ZScreen is an open-source screen capture program for Microsoft Windows. It can upload screenshots, pictures, text & files and put the URL in your clipboard in a single keystroke.
This program lets you take screenshots of Individual windows in Windows 7 (Alt+Print Screen) and actually has the shadow on it. It can also let you select a individual element of a window and take a screenshot of it or crop a part of your screen and just take a screenshot of it. It pretty much replaces DWM and Windows 7 Snipping tool as your screenshot program. It can automatically upload it to a hosting site or just save it as a file in a location you can set. Simply click the link above to visit the site and download it.
Important Advice: Make sure you install it for all users on a computer or else it doesn't take screenshots since it's in Portable Mode.