I just purchased the Cisco Valet and I have to say I love it.
It took about 10 minutes to turn off my computer, unhook my current router and cable modem and then place the valet into the loop. After getting everything booted up... I was done.
The valet earns it's name. It auto-assigned a unique name (at least unique to my area) and a random password (probably not something that couldn't be determined, but unique enough). As an added bonus it includes a segment for guests.
Another added bonus is the nice little auto-config USB key that provides instant setup for any devices which you wish to connect to the non-guest segment of the wireless network. For instance the somewhat "old" laptop that I'm writing this post on (Dell Latitude D510) which has built in WiFi was connected within just a few minutes.
All in all an excellent $90 at Target and a product that I would recommend.