There was a great defcon talk about this. Basically using unicode and registering domain names with a bit flip resulted in results. Like email at Microsoft and some other major companies.
I think the title was dns squatting but can't find it at the moment
That was actually the inspiration for my experiment with this in school, and I also setup one or two domains to catch bit flips but never got any hits. It's a complete myth as far as I have been able to tell (research tells me otherwise by using huge setups, and there are a few commenters here that seem to have first-hand experience, some seeming more trustworthy than others, but clearly not a majority of people). I get that it's (obviously) more than a myth, but I'm not sure it deserves the goo-goo eyes that it seems to trigger with many engineers, either. It's a neat feature slightly above the gimmick status but gets way more attention.
I think the title was dns squatting but can't find it at the moment