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.
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.