Today, I discovered that Pedro Lamas had released a skin for the Windows Phone emulator that allowed it to look like the Nokia Lumia 800. (You can see it here.)
This inspired me to create another new skin for my current phone, the HTC Arrive. (Click here to download the HTC Arrive Windows Phone Emulator skin.) To use either of them, you simply need to copy the contents of the zip file to a specific folder on your computer (make sure to save a copy of the original files):
C:\Program Files (x86)\Microsoft XDE\1.0\
Once you’ve done that, your emulator can look like one of the images below!