From Sase Sham:
Wireless AutoSwitch runs as a service and will automatically disable your wireless card when you connect to a LAN (hard wire) connection, and re-enable the wireless card when there is no LAN connection. This ensures that you are always using the fastest connection for network traffic. In the office this helps reduce redundant network connections, while still helping your employees seamlessly transfer from wired to wireless network connections.
For offices that are wireless security conscious this app makes sure the laptop's wireless card is off when the user is wired into your network. For corporate deployment we do have Wireless AutoSwitch as an MSI package that runs as one process. Wireless AutoSwitch can be customized to your specific needs without extra cost.