Wireless networks are hardly secure - even with WEP encryption!
This is a good read if you want to scare yourself out of using a wireless network. There is some really good info here on how an attacker can get into your wireless network (or how you could do it). I really think that most peope are very ignorant about this - heck, I was until a few weeks ago. I thought I had my wireless network as secure as could be, but low and behold it is actually pretty easy to get into it :(. This is not cool, but it is much better to be informed than to be in the dark about this stuff. It pretty much sounds like if you are using all of the stardard techniques to secure your wireless network, you can still be broken into. Now I just need to find a newer article that explains if WPA can be broken into.