I don't have a floating trem so my guitar goes out of tune very easily if I use my whammy bar (boo hoo, no dry eyes left for poor mee...!) I found that if you down tune a string by several semitones till it's really loose you can do the most trememdous behind the nut bends (which incidentally are pretty easy to prebend and release too), combine this with pinch harmonics (choice of at least 4 notes per open string) you can get some really massive shrieks out of the guitar - kind of Ice #9 sound to it.
My posiest guitar trick involves playing pinch harmonics over the 12 fret E and 13 fret C and bending the C string up to C in steps - firstly to D using just the left hand and then the extra bit using the right hand pushing the string up behind where it's fretted. You get the most evil ullulation of notes passing into and out of phase.