Well I found this for Gimp http://www.slideshare.net/Keef21Moon/how-to-make-a-gif-from-a-video-file-using-gimp Can't say how good it is though, since I use PS Cs5.
There's a program by Jasc Software called Animation Shop 3. I use it and I find it good for exporting GIFs. It's available for $19.99 from Corel, the company that acquired Jasc back in 2004, but Jasc's servers still hosts the software and it's available for free download. I don't know the legality of downloading this software for free so I won't post a link, but it's been available for free a long time while Corel continues to try to sell it.
