Perhaps it's just me but I'm always a bit hesitant to use third party domain checkers. I can't speak for namechk.com but who says the owner of such service isn't logging all entries?

Whenever I want to verify whether a domain is available I use the official whois servers.

Similarly try namecheck.com

It searches the main social sites for handles but also searches for domains and trademarks.

Sweet interface!

Nice indeed!