A way cool screaming harmonic you could do that a friend of mine came up with is strike the second fret harmonic on the b string and the fifth fret harmonic on your high E string as a chord and do a dive bomb and wild vibrato with your wammy bar...It will scream hella loud and sound whicked at the same time.

Tab example below:

.....5............ (E String)
.....2............ (B string)

Strike both open harmonics at the same time (as a chord) then do a bar dive and wild vibrato at the same time.