Actually I don't use any encryption at all. There's no-one else here for miles around to defend it against. If any nerds want to come wardriving past here, they'll stick out like a sore thumb.
The router I have at home has WPA, should I feel the need to switch it on. My home computer (a Mac) sits next to it but uses wireless, whereas the work laptop is cabled to it as my employer has disabled the wireless card. The laptop needs to be constantly connected for VPN.
If I were tempted to replace the long ethernet cable with a wireless adaptor, I would feel honour bound to switch encryption on, as I have access to a certain amount of sensitive data.