Incoming call notification that supports landscape mode
Unfortunately, this isn't something that can be done natively (as far as my research has turned up). The next best thing I found were car dock apps, like Car Home Ultra, which force everything to rotate into landscape and/or display a driver-friendly UI. I'm not sure if it will work for all versions of Android and what other limitations there are but it's worth a try, I guess. If all else fails, try Rotation Control.