it is only somewhat availibe so far as it is pretty new. but since it lights on the sides too it is pretty handy. I have used the liteman xenon flasher it has great vilisiblity from the sides but you only get 4 to 5 hours run time max from a set of batteries. then there is the sparky that lets you choose three colors but does nto have much side to side visibility you can get 15 hours out of it.
http://www.bikeforums.net/showthread.php?t=68186