Most boring IP test
Slashdot pointed out IP spotting, a rather primitive tool checking your IP for prime numbers and such.
Instead of trying to come up with a high score, I was looking for a low score. The lowest I’ve seen so far is gluck, the main debian web server - it has the amazing score of -1.
Update: 129.187.150.128 has a score of -2. And that actually is an IP in a range I administrate. Thanks to Michael for spotting.