Proximity Lock

[xMentality]

Is there a jailbreak app that utilises the proximity sensor? I have a case for my iPhone 4 that flips open, and covers the front when closed, I wondered if there was such a thing that when the proximity sensor was covered it would automatically lock the phone and as soon as it was uncovered it would unlock automatically again, effectively making the case work as a smart cover like on the iPad 2.

I ask because I have the iPad 2 with a smart cover and for some unknown reason whenever I open the cover on my phone I always expect it to come on automatically because naturally my iPad does.

I can't develop apps in any sense of the word so to anybody out there who does, please do feel free to take this idea and go with it if there is nothing out there already. Just please let me know about it.

Apologies if this is in the wrong section.

Wouldn't have to have a cover either, putting the phone in your pocket would work exactly the same way.