Watch the Jeff Beck online guitar lesson by Jeff McErlain from Kings of Tone
Beck's use of the the vibrato bar is unparalleled. He uses it for vibrato of course but the coolest thing is how he uses it to play melodies. He is one of the few players I can think of that can make the guitar sound like a human voice. He can also use the vibrato bar for some great noises and quirky sounds. If you want to really get into Beck's style I suggest you have the bar free floating. That is the only way you can get it to do what his does. CAUTION: Using the bar in this fashion can be habit forming.