Picasion - Great site for creating animated GIF files!
ezgif.com - Ezgif.com is simple online gif maker and toolset for basic animated gif editing.
PicGIF - PicGIF for Mac is an intuitive and agile GIF maker that allows you to create animated GIFs from photos/videos on Mac OS X in a few seconds.
Gifsicle - Gifsicle is a powerful, simple command line tool for creating, editing, and optimizing animated GIFs.
GifGear - How do you make a gif
GifTuna - Quickly convert videos to gifs on Mac, Windows, and Linux