I just bought a PowerMac G4 cube (using it right now in fact), it has the stock 450mhz g4 cpu, and a paltry 384 megabytes of ram (especially under Tiger!). And frankly, it is the most beautiful mac I have ever owned. It seemed really unstable until I replaced the stock 20gig hard drive, so that being said, all my important stuff is still on the pismo.
And being based on a powermac g4, the cube's cpu is upgradable- I don't want anything too expensive, and I could live with 1ghz, I just can't find one. That being said, does anybody have one, or know where to find one for around $200? There doesn't seem to be any available on eBay...