While it's no secret that mobile search (and subsequent advertising) is a hot ticket right now, Microsoft is lagging badly behind search giants Google and Yahoo. While all three scramble to grab partnerships with everyone from HP to Acer (to Dell), Microsoft has landed what is quite possibly its biggest foothold on the blossoming mobile search market yet. By teaming up with Sprint Nextel, customers of the carrier will be greeted by Microsoft's Windows Live search bar at the top of Sprint's menu page when they access the internet from their mobile. Per usual, the search engine can look for "news, sports scores and ringtones" within the carrier's own mobile portal, or "search outside of Sprint's network for local information" such as nearby eateries, theaters, or GameStop locations. While specifics of the deal weren't disclosed, we do know that the two firms will "split the profits" from ad revenue, and that Sprint Nextel customers should see the newfangled box hitting their mobile internet screen right now.