Is there an on-line 'rationality test' anywhere, and if not, would it be worth making one?

The idea would be to have some type of on-line questionnaire, testing for various types of biases, etc. Initially I thought of it as a way of getting data on the rationality of different demographics, but it could also be a fantastic promotional tool for LessWrong (taking a page out of the Scientology playbook tee-hee). People love tests, just look at the cottage industry around IQ-testing. This could help raise the sanity waterline, if only by making people aware of their blind spots.

There are of course the typical problems with 'putting a number on a person's rationality' and perhaps it would need some focused expertise to pull off plausibly, but I do think it's a useful thing to have around, even just to iterate on.