You can jailbreak it, but you cannot unlock the 02.30 baseband. iPhone Dev Team are working on 3.0 right now, so you can cancel any plans you had either. I had to move to 02, which I guess wasn't a bad thing in the grand scheme o things.
If you are still running the 02.28 baseband you can unlock it by preserving the baseband. This is the only way to get a 2.2.1 unlock. There's no new PwnageTool etc for a 02.30 2.2.1 unlock - it just can't be done, at least for the minute.