I solved it when I was a kid not long after they came out. It took about a week. The kid next door had one for about a year and still couldn't do it. He beat the snot beat out of me for doing it too. Karma got him when he tried to pound me again for it when I got back from haying on the farm that summer...oopsie.
I suck myself but have a nephew who is genius in many ways (at last count he has about a half dozen patents). Give him a cube, let him study it for a few seconds, blindfold him and he'll solve it in a flash blindfolded.
The kid (who's now probably 35) is pretty amazing on many fronts.
As I recall, there are a fairly small number of movement patterns required to solve it. If you figure out where everything is at and can remember which patterns to use, you can spin the sides without looking.
A few years ago I got to where I could do it in roughly a minute. I bought another one a few months ago and it took me about ten minutes and I haven't tried since.