to anonymous john
actually John 99% of wi-fi gear which includes routers and especially the Wii do NOT turn off wi-fi. Instead they disable the receive part of wi-fi (because they have lame programmers and it's easier to do so!)
The Wii for example uses the same output power when in standby mode as it does when enabled, but in it uses about 5 to 10% less when disabled. I had discussions with Nintendo last year about this and they refused to do anything about it.
While this wastes large amounts of electricity, people waste even more by leaving it on all the time, even when they are in bed, in work, or on holiday and it is not even needed!
As an alternative why not try Homeplug 200 adapters which can handle 2 simultaneous streams of HD video easily, are not affected by your neighbours and usually not other equipment either?