jarmund

Does someone know the aproximate range of an 15W FM transmitter? (And by that i really mean aproximates... 1 meter? 1 kilometer? 1 lightyear?) If nobody knows, atleast help me put things in perspective: Those MP3 players with FM transmitters, how many watts are they? And how many watts are those that broadcast radiostations' signals kilomiters away? It would be really easy if there was some kind of meters per watt rule... Thanks -Jarmund