On the same idea that Playpumps uses, why not make a bunch of different play equipment that does the same thing (and doesn't make people so damn dizzy!)?
•A see-saw is a simple playground toy, and easily (and historically) makes for a great pumping mechanism.
• Another could be a hard-poled swing (instead of a chain-swing) that works like a pump-jack.
• Another could be a barrel-roll or tire-roll (using stuff that is more readily available), which could be used to turn an Archimedes water-screw.
• Another could be a modified platform teeter-totter that is a big metal disk with guardrails that teeters in all directions.
There you go, an idea worth no fewer than 4 ideas, and helps the developing world by easing their daily water commutes. Somebody, please do this stuff! I'm no engineer...