Re: Using a router with Panasonic TV to access internet.
Search for it on Amazon. It converts wired Ethernet to wireless. So that way your telly can talk to the rest of the world. Should work with your wireless router as far as I know. I didn't say it was more useful than Vieracast - it enables you to get Vieracast, which is the Panasonic Internet service. It is more useful than the Panasonic dongle because you can plug 4 different Ethernet devices into it - eg if you have an X-box next to your telly then you should be able to run X-box live through it as well.
If you have set a computer up to operate using wireless then setting the Buffalo converter up is a breeze.
An alternative to this is to get a pair of "Ethernet over mains" adaptors - I just thought of that 'cos our X-box is connected to the Interwebby thing using a pair of devolo dLAN 200 homeplugs. Work fine and should work for the Panasonic - put one plug next to your telly, the other next to your router, and connect Ethernet cables between the telly and first plug, and the second plug and your router. Disadvantage of this is you only connect one device, and you (supposedly) have to plug the adaptors direct into a wall socket, not an extension cable.
(Our x-box is on a different telly, else it would use the Buffalo converter)