I can play Trace Bundy's Cannon, but not Andy McKee's drifting...
I want to learn another two hand tapping song, ideally a little easier than cannon cos I don't have the time to devote to something huge...
I'm so unique I don't even have a sig.
Try Andy McKee's song called 7-14.

It's in the vein of Drifting but it has more technique and diversity in my opinion, and there's quite a lot of tapping in it.
Try to learn Justin King's Knock on Wood, it's fairly easy as far as two handed tapping songs go, I think.