integrate *own* ruby on rails chat application, is there a gem for that?

So, I abhor using 3rd party API's personally, as it creates extra
dependencies *and* extra possible points of failure for our business.

As a result, no, we're not going to use meebo, etc, or similar (they
spammed us WAY too many times, as well, trying to sell us their
stuff).

Is there a gem for integrated chat into an RoR application? We build a
private messaging system we call fun mail ~3+ years ago, which works
great...but, we "lose" people who then move off site to have convo's
in real time...if we could bundle in chat, we'd keep them on site
longer, and it'd be a more seamless experience (also, if the person
that joins the convo goes creepy, they can block them on our site, and
they don't feel violated, eg, having just given their email out to
somebody who went pervy...it's happened.)

Any suggestions are very much appreciated.

Not that I know of, however I've built something very similar at work
and we were planning on open sourcing the underlying technology in the
near future.

Fred

Whereas rolling your own takes much more development time and -- often
-- doesn't work as well. There's certainly a tradeoff involved, but
I'm not sure that an "abhorrence" of 3rd-party APIs is always
reasonable. (I would *not* want to write my own JavaScript mapping
service...)

My one experience with building a chat application didn't go that well
(that was with PHP, Fusebox, and Mootools, not Rails). It's a lot
harder than it looks...

Best,