NoLockScreen is a new tweak for iPhone available in Cydia that disabled the lock screen, unless you’ve a pending message on it. Of course, this may not be for those of you who use various widgets (e-mail, weather, etc) on the lock screen.
On 3.2+ it will instantly goes back to what you were doing. On 3.1 and below it will show the lock screen for a split second + does animations.
Since NoLockScreen bypasses your lock screen, it means any passcodes you may have enabled on your iPhone will also be disabled, hence giving raise to insecurity.
NOTE: You can turn this modification on or off using from Settings, or by using the SBSettings toggle.
You can download NoLockScreen from Cydia for free.