Auto Screen Capture is an Open Source graphics utility that provides you with the ability to automatically capture the display of up to four screens - an excellent tool for designers, gamers, and testers.
iTop Screenshot is a free, lightweight, yet powerful screenshot tool. It helps you quickly take screenshots, easily annotate or highlight your captured images, and share your screenshots to popular third-party platforms.
Microsoft Snip is a handy little tool that allows you to create screen grabs with the added bonus of voice. Perfect for a concise transfer of ideas, quick work tutorials or step by step directions for driving.