There is this thing I'm trying to do. Synyster Gates does it alot, I think there's one at the end of the Gunslinger solo. It starts as a regular note, and then it sort of fades into a harmonic the longer it is held. Is there a technique to this, or is that just something that happens when you have a good setup? I'm new to guitar, so this may be a dumb question. Thanks.
I think you're talking about feedback...

That tends to happen naturally at high volumes. Standing close to your amp helps too. Be aware though if you have a cheap starter amp you'll be more likely to get a sharp screeching sound than the musical kind of feedback you hear on songs.
Well, if you strum an open string, and let it ring, and then you can make a harmonic with the 12th fret (or 24th) and it keeps ringing.

Or it seems it could be a tapped harmonic, and then he just pulls up on the whammy.
Do you like Bagpipes?

Good for you

Quote by postmortem2006
Perfect metal stereotype;

If you have long hair, apparently your music goes RAGHHHHHRAGHRARGHRARGHHHHHHH.