[ajslater]

Strictly speaking, I don't think these things have a 'size' with a border where you can be inside or outside of a lepton 'surface'. Its a basically a point source with a field effect as far as we can determine. http://en.wikipedia.org/wiki/Classical_electron_radius

I think the article is saying that the field affect appears to be completely uniform.

Technically, if the electron can affect something at a great distance via gravity or releasing photons you could say the size of an electron is many light years in diameter. Or you could call it infinitesimally tiny.

Neutrons and protons we know to be complicated little parties of quarks and gluons, each of which are, as far as we know, are also elementary particles like leptons.

[lutorm]

I wondered about this too. It's not a point, though, that doesn't make sense in QM. So do they mean that the wave function is totally spherical?

Plus I want to point out that it's pointless to say that something is spherical to within 1e-20m unless you also say what the "radius" is. If the radius is 1e-21m it's not a very good sphere at all...

[ars]

Why doesn't a point make sense in QM? Electrons are point particles - they have no size at all.