Interactivity revisited. I've been trying to remember all the recent sites I've seen that allow people to interact in unusual and awesome ways on the internet. Swarmsketch is a prime example. Help me remember some others...
→[More:]
1. Massively Multiplayer Pong was awesome, but it seems to be broken.
2. There was a site with dozens of people drawing at the same time. Wasn't there?
3. Oh yeah, interactive fridge magnets.
4. What was that big collaborative "novel" that was being written one sentence at a time? It would load up two sentences, and visitors would write a new sentence to go between them.

Any others?