Over on the Inside BlackBerry web site they have posted an article introducing the new BlackBerry Protect service - http://blogs.blackberry.com/2010/07/introducing-blackberry-protect

Still only available in beta, the new service will provide consumers with the ability to backup their device data to a cloud-based storage area, remotely lock and change the password on their device, remotely wipe their device, or cause the device to ring if they have misplaced it by logging into their account via a web browser.

You can also track your device via your web browser by using the device's in-built GPS capability, and can also create a message to be displayed on the device screen in the event that it is found.

Read more on the BlackBerry Blog site.