Steve Ballmer at Mobile World Congress.

Whenever reports surface about Microsoft preparing to rebrand Live Search, as happened again today, I wonder if the company has forgotten it owns one of the coolest domains on the Web. It would seem odd to pick something obscure like Kumo, the rumored front-runner, when Microsoft already has the perfect site: Start.com.

The thought occured to me again recently when Joe Wilcox of Microsoft Watch pointed out that Microsoft was reviving the "Start" concept as part of the new Windows Mobile 6.5 interface. Pushing the Start button on the device leads to the application menu. In Windows on PCs, the "Start" button was long used as the starting point for accessing the operating system (and, paradoxically, shutting it down).

Beginning with Windows Vista, the word "Start" was replaced with the Windows "jewel" logo. Still, if the company is intent on changing its search brand, it seems like a no-brainer to go with Start.com, given the word's longtime connection to Microsoft's best-known product. From a marketing perspective, it would be easy and natural to position Start.com as a search portal -- a starting point for the Internet.

What's more, the domain isn't being used by the company. Start.com, once used as a test bed for Windows Live features, was decommissioned two years ago and currently redirects to the personalized my.live.com portal.

I'm sure there are drawbacks I'm not considering. Maybe the company's search marketers are about to blow everyone away with a brilliant campaign putting "Kumo" right up there with Google in brand recognition. Or maybe they've already decided against the Kumo name in favor of something more straightforward.

In any event, if the company doesn't do something with Start.com, it might just go down as the most underutilized domain in history.