Using WPA2 usually keeps out even people in the know because it requires that the hacker use a dictionary attack. (Or a handoff I suppose) Using AES instead of TKIP, (not that it really matters, but TKIP does have one security flaw that has been demonstrated)
To protect against a dictionary attack, you need a strong password. It's not always easy to make a strong password. Using the WPS option (that we both have turned off atm >_<) allows the router to create strong keys for devices, you have to add the device to the network using a PIN number, but once the device is added, it uses the strong key.
Your blackberry supports WPS.
Also, use a SSID that is not on this list: http://www.wigle.net/gps/gps/Stat
Something to do with rainbow tables, no clue how it works or why, but that's what I've heard.
You should also secure your computers by keeping their OS updated.
I personally don't use the mac filtering, some people do. I have DHCP reservations for all of my devices, and I simply check my logs every once in a while to see what's up. But MAC Filtering is certainly one way to go.
I like Lycan's network audit setup. If I was running server services I might want a dedicated PC to monitor and audit the network. If you're hardcore on security you can throw in a honeypot
