Some great replies in this thread. I like hondaworkshop's line: "be predictive, be patient".
My mantra when I'm in this situation: "
BE the accordion..."
This topic came up in this thread as well:
Traffic experiments: a cure for waves and jams
A side benefit of contracting & expanding the space ahead of you and idling along at a low constant speed while the guy in front stops & starts is that you're also improving the fuel efficiency of a considerable number of cars behind you by smoothing out the flow.