Switching between wired and wireless

Looking for a good solution for our users to EASILY switch between a wired and wireless connection and doing this without administrative rights, we currently have users who are taking up 2 ip addresses by connecting to our network with both the wired and wireless connection.

The machines in question are all XP SP2, I am sure this is a no brainer for most but I could use some advice to make this as EASY as possible for our end users.