The local makerspace just had this Titanium PowerBook G4 lying around that I sure didn't see before. Bottom panel was loose and missing all of its screws, and I couldn't find an AC adapter. Figured I'd take it home to test it, knowing my iBook G4 charger would work.
Turns out it runs just fine. 667 MHz Onyx model with a Mobility Radeon, stock 30 GB HDD, DVD/CD-RW drive, AirPort card, and the most pleasant surprise of all - 1 GB of RAM, already maxed out for me! Oh, and the battery actually holds a decent charge, which is more than I can say for that iBook when I first got it.
It was running OS X 10.2 Jaguar with maybe one extra app installed, as if it didn't see much practical use for a while. Since a 1.42 GHz iBook G4 would curbstomp the old TiBook at running Tiger or Leopard (and I find it barely adequate for Leopard as is), I decided to go backwards, install OS 9.2.2, and then set up some games.
MechWarrior 2 runs just fine, Unreal Tournament has some moments of slowdown here and there, Driver is consistent but not perfectly smooth... it's not going to stand up to either of my MDDs in terms of performance, but for a laptop, it's respectable. Kinda makes me want to track down one of the later 1 GHz TiBooks, mainly out of hopes that the Mobility Radeon 9000 fares a lot better for gaming.
Also speaking of Classic Mac OS gaming, now's a good time to remind myself that Pangea Software basically made a bunch of their older releases legal freeware. http://pangeasoft.net/macGames.html