If neither a simple 4-digit passcode nor Touch ID are secure enough for you, you can choose to protect your iPhone, iPad, or iPod touch with a longer, stronger alphanumeric password. That greatly reduces the chances that anyone can guess or brute-force their way into your device and access your data without your permission. What's more, Apple makes it easy to set up.
If you need help choosing a long, strong alphanumeric password, check out this article from AgileBits:
That's it! The next time you want to unlock your iPhone or iPad you'll have to enter that strong alphanumeric password and any time someone else tries to break in, that's what will hopefully stop them dead in their tracks.
What are you using to secure your iPhone or iPad? Touch ID? Passcode? Password? Nothing at all? Let me know what you've chosen and why!
Note: Updated for iOS 7.