If you want to roll your own chat clients now there's XML you can easily get your hands on to get all the information you need. Only grab the other users XML every 90 seconds or less often that's how often our other users updates... yours shouldn't be any better... or unnecessarily bog down our server.
As for the other two I wouldn't suggest grabbing the regular messages more often than once every 10 seconds and private messages more than once every minute.

We'll set those arbitrary guidelines for now and see if that lightens our server load a bit.

vroom | Tim Vroom |