If you care about making skill checks on short notice, I'd recommend Guidance of the Avatar. +20 competence to a single skill check. Enough to pretty much guarantee you'll bluff that NPC, know about the monster's weakness, use that magic device, do the impossible, see the invisible, row row fight the power...
er, where was I going with that?
Oh, right. Skills are useful. Guidance of the avatar is only second level, and therefore broken.