seeking home-grown edible mushrooms

["Brent Capener" <cape@moscow.com>]

     Last year during the pre-Christmas-shopping commercial blitz there was an occasional add for a "mushroom log".  This is a piece of wood that, after being soaked in water and stored in a dark place for a short period of time, would sprout a layer of edible 'shrooms'.  Supposedly, this could be repeated many times. 

      Has anybody had any experience with and/or know how to obtain one of these? 

                                           Thanks,      BC