Online riddles are a craze that seem to be catching on lately.  They challenge your mind and your test your ability to think creatively, and depending on the riddle, require a bit of computer knowledge.  What I'm wondering is, what does everyone think of them, and what are your favorites?  (I think this would qualify under general discussion, becuase you really need to use your brain for these)

 

Anyway, to start the ball rolling, my favorite online riddle by far would be www.notpron.com.  It's a complete riddle, and really opens your mind up.  I also like http://theunnamedquest.tripod.com, but that's in part because I created it.