One of them had little hydraulic ram pumps for sale: he’d made demo models, based on the real one at CAT, intending them for demonstrating the technology to schools or people in developing countries. He had one set up and working, made from copper piping, plumbing fittings, plastic pipe, a plastic lemonade bottle and various other bits and pieces. In some ways it was more impressive than the real thing, because it was made from familiar items and you could see the whole thing working at one go.
The water started in a plastic bin on the floor, flowed along a piece of copper pipe and through a collection of fittings, which forced it up the plastic pipe so that a little squirt of water pumped out about eight foot high. He was adamant that it was only for demonstration purposes but I could imagine real uses for it. It is better suited to a continual, natural water supply, but pouring water into a tank on the floor, perhaps below the outside tap, is a lot easier than lifting it up high. It would water hanging baskets, especially if they were placed one above another, or maybe water the plants on the shed roof. Priming it after it has stopped would be a factor, but provided it is within reach that wouldn’t be a problem. The pump produces some waste water, so ideally it would be placed somewhere spilt water would be an asset. And there are loads of plans on the internet for making real life-size ones.