The common wisdom during the early days of the iPhone (which is a whole 2 years old now) was that it was purely a consumer phone with no place in business. Today it is seen in the hands of a lot of professionals and even has some enterprise type features like Exchange ActiveSync for use with Microsoft Exchange Server and a remote kill facility. However, according to Wired.com's Gadget Lab...

Hacker Says iPhone 3GS Encryption Is ‘Useless’ for Businesses

The article reports that the iPhone's built-in encryption feature is broken and useless.

Here's a tip for those of you who want to or have to keep sensitive information on your iPhone: Encrypt it using a good 3rd party data encryption app. I haven't used Ilium Software's iPhone version of eWallet...

eWallet for iPhone

...but I have used their Windows Mobile versions since around 1997 and think it does a good job of protection data on my mobile devices. The fact that it has been around so long is probably a good indication that it has worked for other people too.