My friend currently has a G3 iMac 333 with 298MB of RAM, 20GB HD, with dual usb. I am wondering if he can run garageband. Doesnt have to be perfect and clean cut, but is it possible to get a 333 imac running garageband. It it getting os x loaded this weekend.

Hate to be a party pooper, but I'm going to have to say no.
My Lombard PowerBook is a 333MHz (its practically the same spec as the original iMac) but it has 512MB RAM in it. I have struggled to get it to run iWeb. It still won't run usably.
OS X is RAM hungry. Even if you stick to Panther and an early version of Garageband, your'e going to struggle. Panther alone will be slow with only 298MB, Tiger even worse. And music apps are RAM hungry too. Even if you manage to trick the installer into installing it in the first place, I doubt it will load fully/properly. If it does, it will beachball for days just opening projects.

Minimum requirements for GarageBand 1 as I recall are a 700MHz G4. I wouldn't waste too much time trying this.
Better off with a classic OS and an old copy of Cubase or Protools.

I would have to say no too... Barageband even pulled out teeth on my old 1ghz emac when it had 256mb ram... So i don't think it will run on a 333g3, sorry...

Garageband can be hacked to allow the use of a G3. It can be done, but should it? NO! Garageband takes some serious hardware to run effectively. I suggest at least a 1ghz dual G4. Dont bother.

garageband didn't run so great on my ibook g4 oc'd to 1.5ghz
id recommend dual cpu/dual core

GarageBand 2 (the iLife '05 version) runs acceptably on my 1.33 GHz PowerBook G4. Interpret that how you want.

i use garage band 2 on my 15in 1ghz powerbook and it does okay. course i also have a gig and a half of ram. so that helps, alot. But when it only had 768megs it was struggled. so yeah, i'll just repeat what everyone else says just to think i'm part of the cool club.

ill just agree with all of you because i dont have a mac anymore sad story...