Coding4Fun USB Missile Cannon is an application that allows you to control a USB foam missle launcher from your Windows Phone 7 device. The project includes a WP7 application along with a WPF app that listens for incoming commands.
This project does leverage code the USB code for the rocket for the HTTP listening application from http://rocket.codeplex.com/
by Chad Z. Hower.
To operate, connect your Windows Phone 7 device to the same network as the computer. Start up the WPF http listener application and put in the computer's name in the phone application. From there you can remotely control the USB missle launcher!
The graphics and XAML for the application were produced by 352 Inc (http://www.352inc.com/