I fly out of a heli training base and have learned to keep a sharp eye out for them, but have to say that they're quite good about announcing their intentions over the radio -- my problem is making out all the details in a complex description
A couple days ago, a Schweitzer 300 was in hover practice not that far from the approach end of the runway and upwind in the crosswind. Me, I'm thinking he's just a little guy, but the rotor downwash made for an interesting bounce and not very good second landing -- should have landed a bit longer.