Right now the easiest way would be to buy a new G4 DP, which would kind of defeat the purpose of the upgrade. I think that when Powerlogix and company come out with their DP cards, they will make sure they work with OS X (to which I assume you are alluding) or else they would be out of business. They do say, though, that they wait until their upgrades cost less than half the price it would take to buy a new computer that is as fast, so you might be waiting a few months.