Wave Energy is being funded, developed and pretty close to being online:
http://www.alternative-energy-news.i...ro/wave-power/
so if we're talking about offshore desal the main issue is probably the excess salt and of course the cost to build a plant large enough to adequately supplement SoCal's ever growing thirst.
I think Tampa Bay is currently using desalination but not sure how theirs is set up.
Haven't heard about towing icebergs, sounds a little bit like the episode of the Beverly Hillbillies when some scammer want's Jed to invest in a giant fan set in the Santa Monica mountains to blow the smog away... unrealistic and temporary at best.