Need a simple GIF maker

[INS-ANI]

I need a simple GIF maker software (or any other) to make presentation animations like this:
http://en.wikipedia.org/wiki/Fileijksta_Anim.gif

I need it to produce a file to be integrated with Microsoft power point files.
Also, i need it not take a lot of time to make a simple animation as given in the link.

Please suggest.

[ico]

Use Adobe Flash and export as GIF.