Nope, I'm still stuck on this.
I'm surprised Apple didn't make this easy to do, especially since there's a legitimate reason why you'd want to do this:
I told my PB to trust the wifi at a coffeeshop. Now I want to un-trust that wireless network, because I no longer have a wifi account w/them.
Every time I go to said coffee shop, it joins that network. I have to remember to turn off the Airport card to preserve the battery. 🙄
So does anyone know how to un-trust a wifi connection? 🙁
(PS: I just do it to preserve battery life, but there's also those wireless networks where you get charged by the minute ... ugh, didn't Apple think about this?)