The QuickUnlock application does exactally as its titled, it unlocked your phone quickly. Instead of taking your phone out of your pocket and sliding to unlock.
Instead you install QuickUnlock from Cydia, the install will require that you re-spring your phone (restart springboard). When the phone has been locked and the screen has been blanked. Just hit the home button three times in a row and your phone is unlocked and you can then launch an application. You have 10 seconds to launch and application or to hit the home button a fourth time, otherwise the phone will lock.
Awesome application. Try it out!