I've never done a triathlon, and I never thought I would.  But I took up running a couple of years ago, and then my brother gave me a very nice aluminum road bike.  My cross training for running had consisted of swimming periodically and now riding.  I was wondering, most of the 2009 tri's are open water swims.  I swim in a pool.  You don't need to tell me that the difference is huge.  I live in Austin, TX and was wondering if anyone could tell me how they prepare for an open water swim during the winter season.  I'm not averse to cold water, just pneumonia.  I'm currently training for a marathon (1st time for that too) in Feb. and then would alter my training to participate in a local beginners tri called The Rookie (300 M Swim, 11 Mile Bike, 2 Mile Run) and hope to progress after I get some basic transitioning and swimming skills under my belt.  Any advice or resources you veteran's or fellow beginners could provide would be greatly appreciated.