Richard raises a good point with Wireless LANs - Security. The company I work for manufactures WLAN equipment amongst other things. Studies we've seen show that a high percentage of WLANs are installed without any security controls enabled.
It's prudent to enable the highest common level of encryption that all your wireless devices support (In order of strength / preference (802.11i - WPA2, AES, WPA, 128Bit WEP, 40Bit WEP). Also your wireless router / access point may be able to block unknown MAC address (The unique Media Access Control hardware address of your wireless client cards) thus stopping unknown devices connecting to your wireless LAN. Finally disable ESSID broadcast (this stops the "name" of your wireless LAN being broadcast for all to see)
I'm not suggesting that's it common for people sit outside homes trying to hack your data but it's not unheard of neighbours piggybacking internet access from your Wireless LAN. So keep the threat of hackers in perspective but I guess if you have security features then you should enable them.
For more info check out:
http://www.weca.net/OpenSection/protected_access.asp
Hope that helps.
Matt - FreeFallFun
