A security flaw in iOS 6.1 allows a person to easily circumvent a lockscreen password and access contact information on an iPhone. The bypass method was demonstrated by YouTube user videosdebarraquito and reported by Gizmodo UK.
To bypass the lockscreen password, a person has to hold down the power button, initiate and then immediately cancel an emergency call. Repeating these button presses in a particular sequence will then provide access to the iOS Phone app. Once the Phone app is opened, users can browse contact information, check voicemail, view photos and more.
Update: Not surprisingly, Apple spokesperson Trudy Miller told AllThings D that it is "aware of this issue, and will deliver a fix in a future software update."