Your comic title, or perhaps your professional name or publishing company is your brand, right? You probably already use it on some social media networks and other sites.
Here's an instant way to check for availability across many such sites with one click. Namechk has you enter your desired name, click, and it tells you whether it's taken or available on a long list of sites.
A drawback is it kind of forces you to ponder whether you care what some of the more obscure sites are for and whether you can spare time to join them, even to set up a placeholder account. But it also helps you spot sites you are considering joining before long.
I'm pretty well covered since a joining spree last summer, but I wasn't on Facebook under my usual name, so I signed up, if only as a hedge.
Now here's the twist. An unstated, but logical use of the site is to enter the preferred user name of an acquaintance and see where they hang out. Perhaps you have developed a friendly routine with someone on Stumble Upon, trading pages for review and joking. Assuming they use the same user name, Namechk is an easy way to find out if they are on other sites that interest you. Consider it a supplement or alternative to the email address search many sites offer, as well as traditional shoe leather stalking. It couldn't be faster or simpler.
Last year, in an amazing feat of prescience, I remarked to Pug, "It won't be long before all the shorter, meaningful .com URL names are gone." Eight months later, try to find one. I was amazed last year when I found a five letter one. Now it's at the point where multiple words plus odd spellings are frequently required. Even long nonsense words of the xkcd variety are gone.
Of course, many are held by speculators, defined in the Devil's Dictionary as people who can see their own wallet with remarkable clarity. So technically, many desirable .com names are still available. They'll just cost you a few thousand dollars.
Which explains how we ended up with Namechk.com.
Here's a partial screenshot of results for the name "SexyThang." The actual results page is twice as long. I'm not surprised it's available for white collar network site Linked In, but it's also open for Facebook. Maybe it's more of a MySpace kind of name -- and indeed, a quick check reveals that there, it's taken.