Helicopters have their own VHF frequency and are *supposed to have* their own controller too!
Where did this come from? I've flown helis a reasonable amount in the US, and I've always been on the same freq as everyone else, and talking to the same controllers.
As for hovering, I've twice been asked by ATC to hover, once in the traffic pattern at Palo Alto KPAO and once flying the heli transition at Heathrow, both times in an R44.