Setting up gas stations in the asteroid belt could work quite well, I would think.
I begin to see the point of NASA's interest in mining the asteroids. It might be possible that water could be extracted from an asteroid by a solar powered satellite, then shipped by cheap, slow, unmanned rockets to rendezvous points for manned missions. Water has some excellent qualities for use as reactive mass in rocket motors, especially those with nuclear rather than chemical heaters, and a ship that only needed to carry enough reaction mass to get from one rendezvous to the next could open up the solar system to manned exploration very quickly. This would make a manned mission to Mars much easier.
But first there is a need to determine whether we have technology that can do the extraction, and whether there is enough water in the asteroids to make it worthwhile. Could a solar powered laser aimed at a point on an asteroid create a plume of water vapor that could be captured somehow and condensed into liquid or ice? Interesting concept...