It was taking Entourage 75 seconds to quit on my TiBook 500 with a gig of RAM. The windows would close, but the Entourage menu bar would still be there and the little triangle would be in the Dock indicating it was running. I could switch to other apps, but the point was, what was taking so long?
I don't know, but it turns out the delay goes away if I close my PPP connection before quitting Entourage. Then it only takes a normal two seconds to fully quit.
--Andy
Mac OS X Hints
http://hints.macworld.com/article.php?story=20011204145437582