I’ve been listening to the JFK tower and approach on LiveATC. It is interesting to listen to the takeoffs and landings at parallel runways like JFK, Las Vegas, or LAX. Landings usually take place on the runway farthest from the terminal and then the planes taxi and hold short of the active takeoff runway. Even though these guys are professionals ATC still has to remind some of them that they must read back the hold short instructions.
A clue to which runway is used for takeoffs and which for landings is that the takeoff runway is usually longer than the landing runway.
LiveATC now has an iPhone app so you can listen when you aren’t near your computer. I just bought it and my home field is listed. You can view details here. For new pilots and anyone learning to copy clearances, I think this app (or the website) can dramatically reduce the time required to learn proper radio technique.