Jailbreak Tweaks

How To: Increase iPhone Security with an Easy-to-Remember Passcode That Changes Every Minute

If somebody really wants to gain access to your iPhone, they'll get in. Phone thieves (and mischievous friends) can easily figure out your passcode just from looking over your shoulder or tracing over the oily smudges on the screen. And if you're using popular passcodes, birthdays, and addresses on your iPhone, you might as well disable lock screen security entirely.