I use my old Beige G3 in my garage as an internet radio server. The iTunes radio tuner sill streams fine. Running OS 9.2.2. I also installed Classilla in case I need to browse the web for something. It all works great. Tried to install Linux back in the day and yeah...way too much trouble. OS 9 runs like lightning on it.

I have an old 400 MHz G4 Digital Audio tower in my computer room that I upgraded the processor on years ago to 1.2 GHz. It is running Leopard and is an excellent file server. Heck the kids still use it to surf the web too. You might want to check out G4 processor upgrades. They are relitavley cheap these days. I think you can even get dual 2 GHz processor upgrades for most of the old G4 towers. Between that and 1.5 GB RAM and a couple of 120 GB HDs in it...not a bad little machine for almost nothing.