Remember when I posted about recycling my futon? Okay, you probably don't, so here's the link to my original post about futon recycling. Well, that time I ended up not doing anything with the futon and eventually my husband hauled it to Goodwill, which gladly accepted it, milk-sippy stains and all. Now we have a cheap-ass futon we bought at Big Lots with a cheap-ass frame, and a floor model futon that we got for cheap at the local futon shop (here's a tip: Do NOT buy floor models no matter how much of a deal you get -- ours went completely flat within 6 months of use). We've got a little extra money coming in and so we're getting a new bedroom futon and frame. But what to do with the old one? I still cannot find any information on futon refurbishment. You'd think that in a country that prides itself on borrowing from other cultures, we would have borrowed a couple of futon refurbishers from their native Japan.
Here's a Metafilter thread on futon recycling that has some good ideas, such as making the futon into a dog bed (or two or three, depending on the size of your futon, I guess).