I think that at some point in the future we will develop nano-replication technology (a la Star Trek: The Next Generation) and there will be perfect open-source recipes for these machines for everything from roast beef to nano-replication machines.
Shortly after that will come the complete collapse of society, because we won't need anyone else for our basic necessities any more. We will just replicate power generators (solar, wind or both depending on climate) and devices for collecting rainwater and making it drinkable. Our waste will be recycled into the raw materials the replicators need (as disgusting as that sounds, I'm sure we'll learn to deal with it) and our internet connections will be made out of wi-fi meshes and long-range point-to-point radio connections.
How can you have any sort of economy with such an absence of scarcity? Well, presumably there will still be some things that are scarce and desirable (like land in nice locations). And presumably there will still be people doing particularly creative things that improve peoples' lives (making movies or inventing new recipes) - we'd just need some way to connect the two.
I'm not advocating for intellectual property as such here (that makes the accounting far more complicated than it really needs to be and introduces artificial barriers to creativity) - instead I'm imagining something more like Nielsen ratings (but for everything) to determine who gets the scarce wealth.
I guess we'll probably always have some form of money, and I'm sure the arguments about how it is accounted for will be as heated as ever. How do you decide on the relative value of the recipe your dinner was made from verses the movie you watched?