Any kid who's played on a playground roundabout has learned this, before they were ruled as dangerous mechanical contraptions and rooted out.

Throwing a ball across a roundabout is an art. Moving on one is tricky (never let go of the frame, or you discover WHY they rooted them out, and how expensive dental work is). Moving a dangling arm or leg on one is interesting. If you rotate the limb in the same direction as the roundabout, coriolis force is enhanced, and your limb spontaneously describes an unexpectedly large circle. Do it the other way, and the circle is surprisingly small.

IMHO, the SF literature on sex in space has missed a whole bundle of fun here, by emphasising the zero-g effects. There are some very interesting consequences of coupled vertical and horizontal motions.

(Some things get easier, and some get rather uncomfortable...)

- Maybe that's why they ripped out all the roundabouts. Kids were getting the wrong ideas ! :-]