The other nice thing with snagit is the range of auto (but over-ridable) output options. FTP is useful for anyone chatting and using a server like dacharts for images for discussion. I note that hypersnap also has ftp but couldn't find one on gimp.
I use this. For freeware it's not bad. http://www.donationcoder.com/Software/Mouser/screenshotcaptor/index.html
Heres another one with ftp capability http://www.hoverdesk.net/freeware.htm Only downside is that it doesnt have the image editing like snagit and hypersnap.