Comment by paulbovbel for Do you have a map already or do you want to build a complete map of your environment? In the latter case, you could try the exploration module from: http://wiki.ros.org/nav2dIt completely explores an unknown environment and builds a map using 2D Laser-Scanner.

Please ask a new question instead of resurrecting a ~5 month old one. If you send frontier_exploration a goal with an empty polygon, it should perform an unbounded search.