This is a neat feature that was discovered on a Windows Phone 7 development blog. Posted by keyboardp, this tip enables Windows Phone 7 users to add transparent wallpapers as their lock screen choice without any kind of hack or jailbreak.

It really is a simple tip and it involves creating or finding a .PNG file which has a transparency layer already added. The problem is that you can only sync .JPG’s to Windows Phone using the Zune PC software, so the workaround is to send the .PNG file to yourself via email, then open the email and save the file to your phone. Alternatively, you can probably also add the .PNG file to your Skydrive account on Windows Live and download it from there. I haven’t tried this approach yet, but I can’t see why it wouldn’t work as well.

You were waiting for a drawback and here it is: many users and myself have not been able to get the transparency to work if you have a lockscreen pin enabled, so if you need to use a pin to unlock the phone, and you probably should, the transparency will just appear black.

For the original blog post plus a video of the action, click here.