Not necessarily the well head, but what ever you call those tanks that pressurize the water.
My friends live on a farm and use one of those large hollow fake boulders to put over their well head to protect it.
They sprayed insulation inside it first. Seemed like a great and natural looking solution.

I have a little concern about putting one on my gas water heater, since the plumbers who put it in told me that I should not have one on a gas water heater. This guy seems to have no concern about that at all. Maybe I should talk to a few more plumbers to see what they say.

The main issue with gas seems to be keeping the burner door/vent and top vent open and free of obstruction. It does seem like
there is more chance that it might be installed improperly by homeowners which is probably why some plumbers might think it best to just not do it at all. I have a gas heater and have a blanket on it and am just careful that those vents stay clear. So far so good and the savings is great plus I'm guessing it will help the heater to last longer.

But I live alone, wash my clothes in cold water only , usually only have a few dishes to wash and I don't leave the water running when taking a shower. I run it long enough to wet down, turn it off while I wash up and then turn it on again to rinse off.

I just moved back here less then a week ago and I did turn the main flame on the water heater to get it up to temp and then I turned the gas valve back to pilot.

I first tried this back in the late summer of 2012 and the gas valve remained in pilot position until I moved out in the spring of 2013 and in all those months, I never ran out of hot water.

Early in 2012, this house was vacant but I was coming over to remodel the kitchen and put in new wiring. The valve on the water heater then was set to pilot and I noticed that the hot water was very hot. So after I moved here later, I remembered that and decided to try and see if I'd have enough hot water with the valve set to pilot and it turned out I did.

Now, this won't work for everyone as one has to be very frugal about hot water use.

The water I have needs to be replaced sometime in the near future and when I do so, it will be another 40 gallon gas water heater with pilot. I give this OP a rec as it would be a very good idea to wrap the new water heater was shown in the video.

Edit: Here is a link to a page which lists alot of conservation tips videos with David Mars:

http://www.youtube.com/playlist?list=UUJKOXkqaYwDAuVZxp0J7k-A

These are easy to understand for people like me who are not mechanically inclined.

I agree that the blanket might assist the heating from the pilot to get a little more warmth from it. I'm guessing you've already looked into the tankless water heaters or solar water heaters and decided against them for one reason or another.
Personally I absolutely need hot water for bathing...it's soothing to my body in every way and is not something I would scrimp on. If I had to heat my water in a kettle over a fire to have a hot bath or shower I'd do it. : )

1) Cost

Tankless water heaters and those high efficient storage tank water heaters with electronic ignition cost a great deal more then storage tank gas water heater with a standing pilot. Since I use so little hot water in the first place, the payback period will be very long.

2) No hot water in case of power outage

Both the tankless and high efficient storage water heaters require electricity to operate. That is not the case with the old fashion standing pilot gas water heater.

3) The storage tank water heater can act as an emergency water supply

Depending on the size of the water heater one has, a person could have 30, 40 or even 50 gallons of potable water on hand in case of an emergency where the water supply is shut off.