I first saw one last summer in Scotland, at Bruce and Bernie's house.
In May, I saw one in the airport in San Francisco, and there were directions on the inside of the stall door. It was the first time I had seen urination "officially" referred to as "Number 1" and the other the other number. Theirs was to lift the handle up for a small flush, and push it down for a large one.
Abbi Traaseth said she saw one in Atlanta somewhere (airport, maybe).
In France, last week, they were everywhere, with different sorts of large and small presses, but all clearly obvious even to a child, who wouldn't be able to read directions or think long about whether to lift the handle up or press it down.
I've seen quite a few of them here in the UK now, too, and some of them just allow for holding the handle down harder for a longer flush.
I'll bring other images if I come back across them.
It might not seem like a big deal to some people reading here, but my whole life we've been made to feel guilty for flushing toilets, and for not flushing toilets--for toilets being dirty, for toilets being wasteful. And none of those go-to-the-moon engineers could figure out a variable flush!?