attachment_fu with animated gifs?

Since you mention that your gifs are smaller than the 800x800, use the form of the resize option that says "only if they need to be made smaller":

"800x800>"

See:

http://www.imagemagick.org/RMagick/doc/image1.html#change_geometry
http://www.imagemagick.org/RMagick/doc/imusage.html#geometry
http://www.imagemagick.org/RMagick/doc/struct.html#Geometry

-Rob

Rob Biedenharn http://agileconsultingllc.com
Rob@AgileConsultingLLC.com