I've just started doing more "gravity defying" and sculpted cakes, and I've been faced with the challenge of internal supports. Last time, I rigged up a "Home Depot" solution with a threaded metal dowel rod, bolts and large washers, with a "cake plate" cut from the lid of an empty tub of gumpaste. A few drawbacks to this method: a) had to cover the metal rod with a plastic dowel/straws, since it's not food safe (though I did put it through the dishwasher first), and b), it still only allows me to go straight vertical.
I just wondered what everyone else uses. Has anyone used reusable supports like http://cakeframe.com/? Looks handy, but I imagine it would be a pain to ask for all the little bits back from your client each time, and you'd still only be able to make one at a time until you got all the bits back (or invest in several sets, which would get quite expensive...).
Would love to hear the solutions you've come up with!