I've got a powerbook G4 1.67mhz 15" model running OSX 10.5 leopard. I use it for certain video apps but lately I use it less and less. It's some sweet hardware, the keyboard is backlit and the screen is large and not glossy. Really I'd like another laptop exactly like it but with a quadcore intel processor running ubuntu. If you go to the apple in the upper left corner of your display and click it you'll see a drop down menu that offers as one option "about this mac." Click that option and it'll tell you about the processor and OS and also how much ram you have. If tiger (10.4) will run on it I recommend that. It's the fastest Mac OS that will run on a G3. I went from 10.2 on a powermac G3 to 10.3 and then 10.4 and each OS was faster than the last. I enjoyed using macs for several years but now I'm almost exclusively using linux. I hacked up a dell laptop to run OSX 10.6 Snow Leopard but after a few weeks of playing with it I wiped it and installed Ubuntu 10.10 on it. I discovered that I actually prefer Ubuntu to Mac now. Linux has come a long way in the 12 years I've been running it. The old iMac can still be useful but it'll need the ram bumped. You can google for sites that tell you how to upgrade it.
