I think someone would do well marketing this in UK.
I think the pub in town has one of these for their hanging baskets. At least, the drips coming from the baskets did look like tap water.
Surprised Hozelock haven't done this already to link into their irrigation systems with drippers rather than using a timer control unit on the outside tap.
It does look interesting, but I'm not sure how practical it would be unless your plants were located in a small area with a water feed.
That sounds like an interesting solution John.
I've often wondered if there is something that would work for self watering individual plants based on a counterweight system, something akin to kitchen balance scales in reverse: I was thinking on the lines of holding a pot by it's rim over a water reservoir and then as the pot gets lighter it is automatically moved down into the water until it is heavy enough to move back out.