Setting up your wireless router to keep the neighbors out.

[sir pball]

15. I'm not maligning you, there's no harm in more security.

I'm just saying that WPA alone is plenty to secure your network against casual intruders. WiFi security is "good enough", but once somebody has the skillset to crack one layer, they pretty much all fall down. In my cost-benefit analysis, the extra work isn't worth it especially since I do let houseguests connect and it's much easier to just offer a password. It's also generally a lot easier for the general public to just set a WPA password instead of tinkering around with deeper config settings; make things too difficult and they'll throw up their hands and give up, leaving things unsecured, rather than slightly less secured than you'd like.

I can't secure my modem since I don't have admin access to it, but if I were worried about smarter-than-average threats I'd flash dd-wrt onto my router, set strong passwords for both WPA and admin access, hide the SSID, implement a MAC whitelist, switch off DHCP and assign each allowed device a random static IP, also whitelisted, schedule access to be completely shut down while I'm out of the house, and spend a couple of hours tightening up iptables.

Or, if I were honestly worried that my threat level was beyond normal security practices, just disable wireless entirely and stick with Ethernet. No security is better than physical security.