Ive noticed this has become a big deal , It would be alswome if there was a built in shout box , make it Ajax or something pro , it would still be nice. We have over 15 members online it would be nice if we could chat to spare time. Or There could be Shoutbox Mod addons . So we can edit it and make it more appealing with more features. And I think you should add a feature where you can take of the side bar and leave the stats at the bottom of the forums or make the forum text a little larger, Plus with description the forums would look bad.
Definitely a feature that shouldn't be included into any core product and best suited as an add-on created by one of the community members. I feel the resources at hand are better spent on features that will be used by the masses.
Dumb question, but this always seemed to be a "tail wagging the dog" implementation:
When a user users loads the Shoutbox, it hits the MySQL database. Number and frequency of queries goes up as number of viewers increases.
Why isn't the Shoutbox coming from a file cache that is refreshed from the MySQL database on a fixed interval? Then you would have a fixed number and frequency of queries regardless of number of viewers.
As for chatting, find a friendly IRC network + free pjIRC web java client. Flash chat doesn't scale well, and other chat options are absurdly expensive.