LockApp

This is a quick and simple hack I put up in an hour. 

The functionality is pretty basic.

1. It provides a lock screen.
2. It disables the home and back and other hard keys
3. It unlocks the phone only if you provide a valid password.

Setup screen is meant to be displayed only first time. You can also setup new password in case you wan to change one.
Code need to be added while changing password which can check for old password and then allow you to enter new password

I'd love it if you could contribute that portion of the code too.