There a few of these around but this one is about the most interesting and accurate I have found, not perfect but pretty close. The idea is to fill out a short survey about your views to see where you land on the political compass. Probably won't tell you anything you don't already know but it's useful for context and comparison if nothing else and I thought it might be interesting to see where the members here stand.
You can take the test here.
And these are my results. I'm a lefty and a libertarian and proud of it.
The rest of the site and the bits about specific elections and parties are also quite interesting if you're inclined to have a gander.