If you're running one of the latest leaks and looking to cash in on a little Christmas cheer, Amazon may have your answer. Their current promo will net you a free $5 credit good towards any app or game in their extensive catalog. All you need to do is download any app or game from the Amazon app store -- even a free one.
This does come with a few caveats however. First off you'll need to be running a leaked version of OS 10.2 on your device that allows for APK installs. If you're good there, make sure you have the latest version of the Amazon app store installed on your device. After that just fire up the app store, log in and download whatever you want. Shortly after (anywhere from one minute to an hour) you'll receive an email that the credit was added to your account. See the full details here.
Your best bet is to go the free app route to get your credit and then to do some recon before you use it to buy an app or game. Some paid apps/games aren't working on BlackBerry devices so you'll want to make sure you don't blow your credit on something that won't even run.
If you have success with all of this, drop a comment and let us know! Hit up the forums for more.