The latest episode of "Ask This Old House" showed Rich Trethewey
installing a Taco D'Mand hot water recirculating pump.

http://goo.gl/lq4aw

As usual, the show doesn't give enough information, so it's hard to say
whether they used the 006 or the 008. In any case, the pumps are about $400.

What do you think about these units? Are there cheaper ones? I was never
in favor of them until I saw that you press a button when you're ready
to use hot water.

My kitchen is a long way from my hot water heater. This device would be
very handy unless it causes diseases or something.