I just took the Perl test (and am now officially certified as a Master), however I'm not convinced this is the best way to gauge ability.
The test took me 15 minutes, without consulting any documentation, and there were a number of questions I found misleading... with more than one correct answer. These were largely conceptual.
I'll take another test, and see if I can get up around the 4.8 level, but I think giving people a chance to explain their answers (in an interview setting) is more valuable than the ability to pick one answer out of five, especially when the terminology's not what I'm used to from the Camel or perldoc.
Still, it's nice to be recognized as a master, better than 90-something percent of everyone else who's taken the test. :)