I sat in a 3 hour vai guitar lesson last month. It was the Alien guitar secrets beef. It really was quite amazing. I didnt expect to get loads out of it, I just wanted to see Vai rock out. But what I came away with was somthing quite cool - no I didnt kidnap steve

Basically he told us all about tuning the ear. 1, make sure your guitar is totally in tune. E.g an E is an E, and not flat etc. Then sing a note. Any note then try and play that note. Sure you will get it wrong for a while, but then all of a sudden your ear will become 'tuned' and anything that you hear on TV or a track you will be able to play quickly and correctly first time. I can honestly say that it works really well.
just a tip.