Most if not all Linksys routers can turn off the radio as well as hide the SSID.
Windows xp sp2 laptop
linksys wireless-g broadband router
Im at a relatives, and this morning the connection was very slow, so I powered the cable modem and router off for a few minutes, and them powered them back on. The cable modem (also linksys) - router connection seems to be ok, as the desktop Im writing this on is directly connected to the router.
However, its not broadcasting wireless, at least Im not seeing its ssid (and it was given a name, its not the default ssid). Ive rebooted laptops, powered router on and off, but still no wireless. I can see other networks in the vacinity, but this one isnt being shown in the view available networks tool.