Perhaps as much as it needs to sharpen its overall Web strategy, Microsoft is working to stay relevant in the mobile game. For the first, there's the rocky but still viable Yahoo play. For the second, now there's Danger.

In fact, the acquisition of Sidekick-designing Danger will pump up Microsoft's access to and understanding of the Internet-savvy and young (or at least youthful) customer base. Heading off a planned IPO by Danger, Microsoft is bringing it into its Entertainment and Devices division. The agreement's price point is unknown, but some reports say that an initial offering may have been doubled by Microsoft in order to prevent Google from buying the company (much easier in this case than it will be to battle the Google machine in its Yahoo bid).

Analysts see the acquisition as a tool to help Microsoft control its destiny as a software maker as consumers move steadily toward smarter smartphones that allow them to perform all the most common online activities without their PCs.

The Danger team, say analysts, has mastered the art of mobile operating system simplicity, a la Apple, which is a skill Microsoft's mobile divisions will need in order to keep up with Symbian and Linux and Apple in the smartphone race. Windows Mobile smartphones are just 21 percent of the market.

Sony Ericsson also wowed the Mobile World Congress this week with an iPhone competitor for the enterprise set, according to CNet News.com. Its new Windows Mobile smartphone, the unfortunately named Xperia X1, sports a touch screen overlay with 100 adjustable panels to coordinate with applications. Initial reviews say it's not as delightful as the iPhone, but it comes darned close. It's expected to be available towards the end of this year.

In related smartphone news, Google and Nokia are doing some friendly wrangling to solidify their relationship, with Nokia adding Google search on some models, while at the same time adding GPS to some phones, a feature that competes with mobile Google Maps. Nokia is, so far, sticking with its no-Windows-Mobile policy -- says Nokia. Microsoft says talks are happening, according to Sky News.

And we'll probably want to remember this name: Andy Rubin. Interestingly, says vnunet.com, Rubin, the founder of Danger, led the Android project, which is now under Google's wing and scaring the pudding out of smartphone makers everywhere. Except, perhaps, Apple. Andy Rubin worked there, too.