At what time control do you stop recording your moves? I've been to a 15|2 (Fischer) tournament where it was not necessary to record your moves and I've also played in longer games where it was expected. My question is at what time limit are you no longer expected to record your games (generally speaking)?

More specifically, would you expect to have to record your moves in a G30 tournament?
Anything less than or equal to G/29 does not require you to record moves, according to USCF. Otherwise known as Blitz and Quick, they have a separate rating for those time controls.

Reference: An Introduction to
USCF-Rated Tournaments [PDF]

So, yes, you do need to record your moves in a G/30, because that is considered Standard time control.

There is a rule that allows you to stop recording once you (or your opponent) have less than 5 minutes on the clock, in Standard time control games. See #7: USCF - FIDE Rule Differences - 2 Columns

Additionally, if you have an increment of 30 seconds or more, it looks like you have to record moves regardless of the time left on the clock. (I wonder if people really have that sort of increment in tournaments.)