My wife's Titanium 667 MHz G4 PowerBook had a hinge that froze and broke away from the lid. She continued to use it for a few months, until the 2nd hinge broke away from the lid. :-(
It's a work machine, so she asked around about repair/replacement options. She was pleased to learn that it's a common problem and a company called [link|http://www.macresq.com/store/index.php|MacResQ] repairs one or two hinges for [link|http://www.powerbookresq.com/detail.php?prodID=P009742|$269].
They also repair [link|http://www.ipodresq.com/menu.php|iPods], for those who aren't mechanically inclined. It's obviously cheaper to do it yourself if you can. I'm glad it worked out well!
MacResQ seems like a good outfit, but we don't have any experience with them just yet.
Cheers,
Scott.