I took these pictures last night at the front of my house. The long-tailed visitor is a ring-tailed possum. Probably the reason I could get so close without it scampering off is that it was engaged in a face-off with next-door's cat (sitting on a wall at the far left of the second picture).
After I took these pictures, I had to go inside to check something on the stove, and when I came back both animals were gone, so I don't know how things ended up. I think cats sometimes attack baby possums, but this one was pretty big and I imagine it could hold its own.
Possums are fairly common in the Australian suburbs, even in inner areas.