We've covered quite a few events, tutorials and whatnots where Windows Phone 7 owners are able to get their devices unlocked - be it through homebrew or via the official channel with developer subscription. We've now received word from a reader who explained how signing up to DreamBuildPlay will provide you with a year developer trial, which you can use to unlock your device once you've passed authentication.
We've just tried this out for ourselves, but unfortunately we weren't given a redemption code to use for a 12 month trial with AppHub. While this competition has unfortunately filled up its redeem code limit, we urge everyone to keep the lookout for other events that offer a free developer subscription, should you be looking to unlock your device without paying the $90.
Thanks for the tip TrentTech!