Neat! Though, on Ubuntu with Chrome 9.0.597.98 I never got loaded after 2 minutes. This could just be due to traffic load though. However, I was able to see other people scribbling, which was still fun.
At some point I will have to enforce a harder rate limit, and/or build better spam protection. The app has been pretty much unused for the last 5 months though, so there hasn't been any real reason to focus on that part :)