MOBILE DEVICE SOFTWARE DEVELOPER Google has started rolling out Android 2.2, the latest version of its operating system for smartphones, netbooks and tablet PCs.Some Nexus One users started to notice that the latest version updated itself over the weekend.People had been expecting Google to do a roll-out in the next few weeks after the outfit tweeted the announcement last week. The early installation surprised quite a few.However not everyone has got it yet and it will be staggered over a couple of weeks. Although if you want to manually install a build there is nothing to stop you.Android 2.2 has a number of improvements although the one that is first noticed is the speed.Sadly the new EVO 4G, which Google gave to all attendees at Google I/O, which runs a customized Sense build of Android, is not going to have 2.2 for a while and has gone from cutting edge to slightly back-level in just a week.