Chlorinated Water - Not Good for Plants

#1
A lot of towns use chlorinated water in their water supply - and it can be a major mistake to use it on your plants.  However, some say the chlorine is gone once it goes thru a garden hose.  Is that true?  Anyway, what are some methods of removing chlorine from water and is there water you can get, other than rainwater, that is chlorine-free?