I bought some tomato cages at K-mart many years ago that I still use. They are made of pretty stiff wire and nest together for storage.
I've looked for more like them, but all the ones I've found lately are made of thinner wire. The thinner ones end up bending over with my plants when they are in full growth, and I'd rate the newer cages as worthless.
Fence wire works pretty well in terms of giving support, but isn't good for storage because it doesn't nest like a cage.
Cattle panels give good support and can be stored flat together.