We have had several raccoons harassing us lately, along with many rabbits (mainly in the garden, but I generally grow enough for them too.) and two families of opossums.
I actually have had a 'possum living in my garage, I have tried to sit and wait it out, but it has more waiting skills than I.
I am looking at setting up a baited trap (free to borrow from the Humane Society for a week), rather than my first instinct of just shooting it. For that to work, one has to first have a clean shot. It is too fast and I am impatient.
(Also, I do not want to shoot up all the cool shit I have in my garage just trying to get rid of a tobacco eating 'possum. Did I mention it ate half of my really fancy, expensive, pipe tobacco?)