I get possums visiting but they don't ever stay around our house. We have motion detector lights that flash on and that (I think) really disconcerts them, as they like scavenging in the dark.
If one is particularly persistent, I've sprayed it with the hose which really scares the B's out of them but doesn't hurt them at all. This works for raccoons, too but they are much more persistent and less afraid of the lights, especially when the mango tree has fruit.
