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.

It does not have a screen where you can enter the password yet,
you'll just have to set it yourself in the code.

If you really really need me to add that screen, do drop me a line.

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