I was somewhat to disappointed to go on SnagIt's download page and find out the application was not supported for Mac OS X. However, I didn't have to go far to find Jing, created by the same company that brought you SnagIt, Techsmith.
And even better, Jing is free.
Techsmith launched Jing as a project back in July 2007, and it's no secret they might come out with a premium version. Currently, Jing uses screencast.com to host files and provides the user with 2GB of storage and 2GB of transfer sound. After capturing an image or video, the user can:
1) add text, arrows, or highlighted selected areas
2) instantly grab html code and imbed the image or video to their site
3) upload the file to screencast.com, flickr, ftp, or the user hard drive
Jing doesn't offer the same user functionality as SnagIt, and they explain this reason in the QA section on their website:
"...the key difference is about workflow. Jing is designed to be fast-visual communication shared with others in a variety of locations. Capture. Annotate. Share."