I guess Andre is talking about this Brainstorm: another_way_to_lock-unlock_the_device

But I'm not sure. As far as I know there was also a other one. But I couldn't find it.
The Topic from this Brainstorm doesn't fit. But Solution #1 is the thing the original Poster is searching for: Support some kind of customization on the lock/unlock "screen"

Every time when someone points a other one to a other Thread, Site or Area a Link would be really nice.