Snagit, which is the best screen capture software for Windows, is now available for Mac as well. You can head over to techsmith/snagitmac to download the first Mac version of Snagit for free.
Though Snagit for Mac isn’t as feature rich as its mature Windows cousin, there’s a new "all-in-one" capture mode in the Mac version of Snagit that lets you screen capture any particular region of the computer screen, the full desktop or even a scrolling region (like a long webpage) without having to change the input mode before that capture. That’s surely a big time saver.
Snagit for Mac is still in an early beta stage but am hopeful that the final release would offer one-click integration with popular web services like Flickr, Twitter, Screencast.com, etc. for sharing screenshots. Jing for Mac, another screen capture and screencasting tool from TechSmith, already supports social sharing.
Snagit requires an Intel Mac running either Leopard or Snow Leopard.