I think you can get like multi-remote "Wi-fi" remote's now. They are like tablet type things. Can't remember where I saw them or how much they are but for anything over 30 meters, a Wi-Fi solution is possibly your only option.
There's also an App for the iPhone which I think does the same thing (basically remote desktop) using your iphone as the mouse.
http://scientific-soft.com/mobile/index.php/menu-iremot...