Love all the ideas, this sounds like it could be really fun!
I know I'm the little n00blet here, but I have a suggestion which sounds a laugh. Maybe if we did that family photo idea (with the sticking together of pictures), then someone with a morphing program (I used to have one, but lost in computer rebuild) do a sort of seperate picture of us in our forum 'Avatars' (eg, Havoc being a Tiger), then make it morph back and forth! Any good?