Our house originally had a timer controlled recirculating hot water system.  During the winter this recirculator was losing 250 kWh worth of energy per month.  I connected switches at each hot water location.  Every touch of the switch runs the recirculator for 10 minutes, saving most of the 250kWh / month.

I wish I had installed a second hot water heater at the far end of the home.  The standing loss is not significant.  I don't think gas or electric fired instant hot water heaters are reasonable solutions.