http://www.poseysail.com/demo.htm
Both the 'Advanced Racing Simulator' and 'Sailing Tactics Simulator' have the laser as an option.
Both these demos are limited to ten uses then they stop working, it also cuts out before you real the first mark
http://www.sailsimulator.com the demo doesnt have the laser (soling only) but the full version does (costs money)
Previously known as Tacticat, http://www.sailx.com/ is a tactic sailing simulator where you can sail lasers, skifs, cats and big boats. I really was hooked on it mounths ago.