That was fun. If you like this sort of thing, "Heavy Planet"[1] is a good hard scifi book set on Mesklin, a fictional super-Earth which spins fast enough to make gravity significantly less at the equator. It's also a good adventure story, if you like 1950s scifi.
How does this compare to Mission of Gravity? I've had that on my shelf and haven't got around to it yet. It's a very cool setting, and the author was writing it before we had all the research on the subject we have today. And he was correct thankfully!
He actually wasn't 100% correct. If you get the omnibus "Heavy Planet" edition (including a sequel novel "Starlight" and some short stories), it is explained in an appendix that Hal Clement's estimation of the gravitational field was somewhat off, resulting in erroneous values for the maximum field strength at the poles.
Still, Hal Clement did a bang-up good job, and the error (or correction there of) doesn't negatively affect the story at all.
[1] http://en.wikipedia.org/wiki/Mesklin