#1
The band called Earshot, have a song called Wait and at the start of the song there is a weird ring/plugging in noise..I don't know how to describe it. Does anyone know how its done?
#2
thats just feedback man, when a guitar amp is cranked up it creates a harmonic ring, so just get a tube amp with a good amount of gain and turn it up up up up up
Gibson Grand Concert Acoustic
roland AC90

I mean this one time I was jacking it pertty hard and was making noises and what not

You, my friend, are a genius!
#3
It sounds like feedback to me. You strike a chord then you silence the strings and the amp feeds back. It sounds like he has a really mid-rangy high gain sound so if you were to hold the guitar close to the amp it will feed back.
#4
I also think it's high pitched feedback, but if you don't want to crank your amp loud enough to get that, you could get a similar sound - though not quite the same - with a pinch harmonic.