I once tried to be smart and actually registered michrosoft.com (a common mispelling). I think it would have been a good idea, except for everyone was probly scared microsoft would sue them until they went flat broke....and then sue their entire family....and then sue their kids...and then one day their kids kids, you get the picture. That was back in the days when domain names cost 75$ for a min of 2 years. Biggest waste of money of my entire life.
that was the end of my domain trading carreer, although i just recently bought like 10 3 letter domains...probly a waste too. Oh well. I still dont understand domain trading.