I don't know about tours of the tower, but you might consider hiring a Cessna 172 and a flight instructor (at a local general aviation airport having a control tower). Aside from giving Uncle Bob the best possible tour of the airport, you will hear (and maybe participate in) plenty of ATC radio chatter. Also, a flight instructor can often get the tower to do cool things such as testing the colored-light-signalling system (used for directing aircraft with radio problems).