If you're a Windows Phone user, you'll now be required to update your device's OS to Windows Phone 7.5 to access the Windows Phone Marketplace, update your apps, or download new ones. Microsoft warned us about the shift just a few days ago, but the update was pushed to most Windows Phone users last fall. Chances are you're already running Mango, but folks who are still on version 7.0 will soon start seeing errors upon attempting to connect to the Marketplace. Now is as good a time as any to upgrade to version 7.5 and ensure uninterrupted access to your app updates. If you're not sure what version of Windows Phone you're using, Microsoft's FAQ should help you get up to speed.