I currently have a good, working network. There are 3 desktops and a printer connected to the four ports of an ethernet router which in turn is connected to the cable modem. At Christmas I was given an (apparently used) roku box, plus my wife was just given a Nook eReader. Both of these want a wireless connection. (Actually, the roku can use an ethernet, but because of the way the house rules are, I can't get an ethernet cable to where the roku will be used. Very nice hardwood floors that may not be drilled through.))
Anyway, I'm wondering if it is possible to add wireless for just the new stuff, without making my computers visible to anybody who drives by with a wireless laptop. If so, how?