Converting a multi-page PostScript to an animated GIF
convert input.ps -delay 200 -rotate "90<" output.gif
Tip: Alter the speed of animation
To set teh animation speed use
convert input.gif -delay 200 output.gif
Tip: Continuous looping
Some viewers, especially some version of MS Powerpoint, only play a single animation cycle. To make it continuous you can use the option -loop with convert:
convert input.gif -loop 999 output.gif
NOTE: Some time Powerpoint requires extra settings for continuous looping of GIFs. Go to the "video tools" menu, which contains "format" and "playback". Under the playback menu, there is a button "Loop until stopped". Click on it, to allow continuous loops! (Thanks to Jean-Noël for this)