For us it was a toss-up between ChatBlazer and DigiChat. I think they are pretty close, but DigiChat appears to be a little more feature-rich, and has a prettier interface.
I am in the final stages of testing the ChatBlazer implementation on my site, with direct log in, nickname assigned from your cookie....pretty basic really, but it worked a treat last night. I'll post back when it is fully operational...right now I turn it on for testing and bug-hunting!!
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Tony (Vipermad) Rickard
Viper Club UBB Admin