I am using Microsoft Windows Mobile phones for last two years, and will never go back to a non Windows Mobile OS again. It does everything I need, and I mean everything. I have installed about 100 applications and games on it, and truly love it.
We have also Apple iPhone on the market, which some people believe is going to be awesome. Or, at least, that is what Apple says. They claim it is revolutionary. Liars. The truth is iPhone is obsolete.