iWarnU for iPhone

From Cyan Media:

When the application is triggered using the accelerometer an alarm of your choice is activated. The alarm can also ring a nominated telephone number so you can listen into the phone itself. Your phone could be placed in a handbag, motor vehicle or just left on your desk, once moved it will sound an alarm, play and display a message or ring a nominated number. It will also log all movements of the phone showing date and time. iWarnU has uses from security to practical jokes. Version 1.1.4 includes minor graphics update, and memory leak fix.

Note: The "Download Now" link directs you to the iTunes App Store, where you must continue the download process. You must have iTunes installed in order to open the link, and you must have an active iTunes account to download the application. This download may not be available in some countries."