Basically, they test word association, which apparently can show unconscious biases. It sounds simple, but there's actually a lot of interesting stuff behind it. The main site, of course, is here:
So here's an interesting thing for those of you willing to step out on a limb... take the racial test (black vs. white). It's on the "selectatest" page I linked to above. It requires around 5-10 minutes of mostly uninterrupted, undisturbed time. Post your results in the comments. I'll post mine once a few other people have posted theirs (I've already taken it, but I don't want to influence anyone). Go ahead...! I dare you.
In return, if you want, I'll take any of the tests you ask and post the results, no matter how they turn out. How's that?
Update: Take the test a couple of times, if you can - people on my f-list seem to be getting variable results and I'm wondering if the test is that flawed, despite what they and the source I got it from report as consistent trends, or if you guys are just weird. Probably a little of both.