Word that Steve Ballmer is in Stockholm trying to convince Sony Ericsson to use Microsoft’s Smartphone operating system for its cellphones. Remember that so far no major handset manufacturer – apart from Samsung (and even that seems a bit iffy right now) – has agreed to put the Smartphone OS on its phones. While it seems somewhat unlikely that Sony would willingly give Microsoft any ground in the cellphone market, the Sony Ericsson joint venture is bleeding cash, and Ericsson has been dying to get out of the deal for a little while now. With Microsoft desperate to grab marketshare for its new OS, it’s not totally crazy that two desperate parties would be able to come to craft some sort of arrangement. Ballmer is already denying rumors that Microsoft wants to buy Ericsson. But just imagine if they bought Ericsson’s share of Sony Ericsson and all of a sudden Microsoft and Sony found themselves in bed together. Sony must have put some sort of clause in the joint venture to prevent this sort of thing, right?