I’ve blogged several times about the desire to disable the wireless card when the wired card is connected.
A comment on one of my older entries points out that there is free software to do this now.
http://www.wlanbook.com/disable-wireless-connected-lan-xp-vista/
http://www.wlanbook.com/bridgechecker/
I’m now using SEP11 for this but passing it on in case others are still looking for a solution.
My older articles:
New version of Autoswitch out
Disable Wireless when Wired Connected
SEP11 and Wireless Management
Disable Wireless on LAN Access