If you have published a PhoneGap application to any of the existing app stores (and if you haven't, then you really need to get on it!) then you should consider taking Microsoft's Windows Phone Porting Challenge. Simply port your application and test it in the Windows Phone Emulator and then publish it to the Windows Phone Store by June 30th, 2013. Prizes for winners include Surface Pros and Windows devices. To be clear, those of you with Macs (like myself) can test with VMFusion. I have and have had success seeing my content show up on my Windows Phone device. To help you get started, here's an introductory video on PhoneGap and Windows Phone. (By the way, the video is having issues loading for me at random times. Sorry if you don't see it.)
Note - even if you haven't published a PhoneGap application to an app store yet, you can do so and then submit your app to Microsoft!