These happen on a semi-regular basis. It isn't really a festival, but a screening of animation from SIGGRAPH. Here's what I got in the old email:
COMPUTER GRAPHICS Special Interest Group (SIGGRAPH) of
the Association for Computing Machinery (ACM)
-- COMPUTER ANIMATION FESTIVAL --
Thursday, February 23, Room 206 Claxton, on the UT
We will be viewing the 2005 SIGGRAPH Computer
Animation Festival, Part II. These reels were juried
from international submissions, and they were first
seen at the 2005 SIGGRAPH Conference this past summer.
If you weren't at the Conference, this is your chance
to see it.
Free admission. DOOR PRIZES.
For thumbnails, see