namechk

From the website:

Check to see if your desired username or vanity url is still available at dozens of popular Social Networking and Social Bookmarking websites. Promote your brand consistently by registering a username that is still available on the majority of the most popular sites. Find the best username with namechk.

Below is a screenshot where I checked for "mikeintexas", my own nom de plume in Groups and in Blogger. I know there was someone else before and several afterwards, according to Google searches I've done on the nickname.

Click the pic for a larger view.



namechk