Rollin' with it: The Zero-Prep GM Challenge!

The plan, following my jaunt into free-flowing GammaWorld goodness, is to structure my game-mastering so that:

• There is no "Adventure Path Railroad" my players have to follow, but there is still structure and plot.
• The heroes can choose their sides and actions without having to worry about derailing the abovementioned plot-train.
• I have minimal prep for each adventure / story arc, and can easily take the game wherever the players choose.
• We can roll dice, have fun, and tell stories without anyone having to write (or, for that matter, READ) pages of story and fluff that may not end up being relevant to the story anyway.  See points 1 and 2.

Rollin' with it: Lessons learnt from GammaWorld...

...or: The ongoing Misadventures of Murtt and Bugeye.

My GW campaign is on hiatus - we've rotated DM, which means I get to play. Yay!  We'll be playing Pathfinder, but that's irrelevant...  I've been thinking about this for a while, as GW has been zero-prep for me over the last month, but still satisfying and great fun to run.

SO: What have I learnt from running Gamma World?