You might want to consider Otakon.
OTAKON 2003 (AKA Otakon X) will be August 8-10, 2003 in Baltimore, Maryland. Some time before New Years the submission guidelines & contest rules should be posted at http://www.otakon.com
. (As soon as they're ready, basically.)
We accept AMV submissions on both tape and CD, and allow submissions from people outside the U.S. and/or those who won't be able to make it to Otakon in person. We also show all the submissions at the con. Usually about 28 AMVs make it to the finals and compete for awards/prizes in the contest at the convention (audience votes for their favorites in each of 5 categories).
AMV Contest & Screening Coordinator