acphydro said:WiFi lan adapter sounds the same as the wifi usb device. Except wired. If its CAT5 wire it can easily go 75ft without problems probably up to 100ft. BTW if your wii isnt far away from your router you may consider getting a Wii LAN adapter which would let you plug in your wii to your router directly via a cable provided you can find one. Although I don't know currency conversions [im in us] I'd assume that doing what you want to would cost as much money as buying a new router. However if your ISP's device is a modem/router you might want to go that route as sometimes without proper setup a second router can be a pain in the ass since its gotta also go through the first so both have to be configured correctly. If you just have a single modem then its no problem.
But if your goal is to get that sucker connected ASAP then by all means your solution is perfect. Regardless if thats what you want to do I suggest you do it.
Cat5e cable can be run 200-300 feet without issue in most cases.
A wireless router will give a range of 100-150 feet in most cases, but it varies a lot depending on how many walls/floors in the way, and house construction teqnique.
Just go buy a wireless router, like the Linksys Wireless-G.
Plug your cable modem/DSL into it, follow directions to setup.
Tell the Wii to search for wireless, and you are done.