I find this lock screen really cool because it does not use the numbers. Its a keypad with circles and you drag your finger and make a shape and it unlocks. Here is a picture of it.
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If you want it you need a Jail Broken ipod touch or iphone
you need cydia or icy but not sure for icy (I got mine from cydia)
Once cydia is open go to search and type androidlock
It looks Like first one in pic below.
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Have fun with your new Lock Screen