This site gives ratings for web sites and blogs. Enter the URL and it will give an MPAA-style rating, G, PG, PG-13, R, or NC-17.
It’s kind of amusing and I’m a bit curious about the algorithm--it appears to be rather simple and unsophisticated, based on the frequency of four-letter words plus sexual and violent topics. It does not rate an entire blog, only the blog’s homepage. So typing http://www.wordorigins.org into the web form will yield a G rating (at least for today).
Give it the URL for the page on cunt, and it gives a PG rating. The Big List entry on fuck gets an NC-17.