UPDATE: Apparently, GoDaddy using ".co" as the default rather than ".com" was just a test (Also see: CoInternet).
Well, apparently, buying a .co domain name (in lieu of or intead of a .com domain name) is all the rage now...at least it will be soon, hopes GoDaddy, the largest broker of domain names, which has now made ".co" it's default choice. The .co domain typically costs more than it's .com counterpart, if available, but is more "trendy," because it's new (or so the theory goes).
The .co domain started out being the designated domain name for the country of Columbia (much as ".me" started out being the domain name for Montenegro, then became popular for personal blogs and websites, as people began to think of all of the things people could do to/with "___.me"). Now, the presumed meaning for ".co" is "Company," or "Co.". Oy - in addition to the punctuation nightmare for spell-checkers and print media, there is another problem with using this domain name. If the ".com" name is already taken, there is the potential for a great deal of confusion due to typographical errors.
Some people are taking advantage of that, of course, and buying the ".co" version of popular ".com" names, and setting up spam sites. Others, like Overstock.com, are buying the ".co" equivalent of their own name, to protect their interest - type "o.co" in your browser, and see what happens. For most businesses who have already purchased their ".com" names, however, this is going to be a distractions and annoyance, as they will now have to decide whether to rush out and try to purchase (or possibly bargain for later) the ".co" version of their name.
For some, the ".co" might be quite useful. Twitter is using t.co help guard against malware. This is smart, because no one really needs to remember the domain name, or type it correctly, but Twitter has reserved it for use later, if the trend toward using your company's first initial and ".co" becomes an internet meme (sort of like the "J-Lo" craze).
Jennifer Pointer (e-mail) is in Tulsa, OK. She promotes a simple, a low-tech approach to effective online profile management, search engine optimization and social networking.