Very interesting reading about the survey of McAfee:

What’s In A Name: The State of Typo-Squatting 2007
us.mcafee.com/root/identitythe ...

Yeah, there's typosquad versions of almost any popular domain name; Also, unregistered .net or .org versions of domain names that have .com (and similar) are very popular. In particular when the domain name itself is not a trademark – but then again, domain grabbers do not really care about trademark infringement either.

Thank you for this post!
I already noticed this some time ago an thought that in fact google is spamming his own index by paying typo-quatters and spammers.

Wanted to add this specific number from the McAfee report "Google-enabled advertising shows up on 19.3% of all suspected typo-squatter sites in this study."