Maybe you could have more events that take place through the forum (I see the winner of the week threads as an example), and perhaps more about combining animations, effects and sound to make Stykz Movies!!! (I happen to like making a movie out of other people's anims than making my own 'mations
Also, some incentives for being active could be implemented. I'm thinking of special sig banners for the most active users, zaniest users, nicest users, etc, you get the idea. And then also maybe give a special banner to users who are active on holidays (I'm thinking of what Notch did in Minecraft - he gave a whole bunch of users capes for their avatars on New Year's Eve once).
Just a few thoughts (I am also trying to be active, expecially since this is the only forum I can be on).