Helio has tapped Goldman Sachs, its longtime banker, for a new project, we hear. Signing up a banker is usually a sign that a company is putting itself up for sale. Helio, Sky Dayton's wireless startup, began life as a joint venture of EarthLink and SK Telecom, the South Korean phone company. But EarthLink washed its hands of Helio after the untimely death of CEO Garry Betty, and on Tuesday, Dayton and most of his EarthLink-loyalist management team were ousted. Now SK, too, may be looking for Goldman to rid it of a cash-burning child. Why would anyone buy Helio? Not for its tiny user base. Possibly for its innovative phone designs, like the Ocean, and mobile friend-finding services. It is unlikely those will reclaim the hundreds of millions of dollars SK poured into Dayton's dream.