iPhone & iPad security is extremely important these days when you have your corporate and personal email, contacts, and calendar on there. But think about everything else you may be using on your iPhone/iPad that could be utilized to steal personal information if your device gets lost or stolen: Social networks (LinkedIn, Facebook, Twitter), E-Commerce sites (Amazon, Netflix) and any other site/app combo that may have your Address, Credit Card or Bank information.
Well this post from How To Geek outlines how to Remotely Lock & Wipe your IOS5 device should you find it is no longer in your possession.