That sounds like something I'd be interested in buying! I'll have to give that a runby with my mum, see what she thinks. Ours is electric as well, and it really does kill the pocketbook. Since I've been living in a construction site most of my life, I've learnt to have 2 or 3 showers a week, and make the clothing last haha, because you never know when the parents are going to rip out the bathroom and leave you without it for 4 months so you have to shower at the gym.
I installed a timer 2 years ago now. It makes little if any difference on my electric bill. Time to go solar. For about $250 you can build a working solar water heater and never buy hot water again. For about double that you can build a "cadillac" system with a solar circulation pump. It will pay for itself in no time.