iPhone Data Protection
Now that Apple has released IOS 4 there are a couple of funky security features that you can make use of, namely Data Protection and strong passcodes.
“Data protection enhances the built-in hardware encryption by protecting the hardware encryption keys with your passcode. This provides an additional layer of protection for your email messages and attachments. Third-party applications can use the data protection APIs in iOS 4 to further protect application data.”
For more information on how to enable this feature, please see the Apple article HT4175.
Stong passcodes means that you can finally do away with the standard 4 digit PIN to lock your iPhone and you can now set up complex passwords instead. To enable this, go into Settings->General->Passcode Lock and then turn off Simple Passcode.