Finding similar domains that are reg'd

[malcolm321]

I'm looking to sell a domain I have to an end user and have been looking for websites with similar domains. When I google the keywords, lots of sites come up and I'm contacting them as well, but I don't want to miss any sites with very similar domain(s). I have so far found one, (if my domain is keyword.com, this one is bestkeyword.com) but I feel like there are probably more out there. I know you can use GoDaddy to find similar available names, but what about similar registered names?

Derek