I'd actually like to see the Greens and the Libertarians get together and run a candidate. Oliver (Libs) got 650,126, and Stein got 862,049. Put em together and you've got enough voters to actually have a reasonable chance of grass roots momentum, exponential involvement, compounding returns on capital / effort, large donor buy-ins, numbers that meet news media minima for free coverage, and long-term viability.
The Green's usually are identified as being libertarian socialism anyways, so it would not be a horrible cooperation to hang out with Libertarians and discuss how to make environmentalism; nonviolence; and social justice work with civil liberties; non-interventionism; and laissez-faire capitalism.
And then they could state that they're not a spoiler, since they draw voters relatively equally from what might otherwise be Democrats and Republicans.