For three years, Bob Odenkirk and David Cross have been answering the question: What would it be like if "Monty Python's Flying Circus" had been made for HBO? Their no-holds-barred approach to sketch comedy, "Mr. Show With Bob and David," returns for another season at 11 tonight on HBO. For added viewing fun, make a flow chart showing how each sketch segues into the next. Also tonight, John Glenn week kicks off with the three-hour "Return to Orbit," beginning at 7 on the Discovery channel.

