Thanks for all of these terrific suggestions!

I'll be back to add a couple of other open-source links.
MITx was mentioned, yes? TED also has some interesting material.

Coursera and Udacity are also on my radar, though I've not checked either one out very thoroughly at this point, so I can't say what they have which is physics-specific.

High school level material (not just physics):

SAS curriculum pathways.

Oh-- for lab materials, Labpaq and esciencelabs.

Schrödinger's cat walks into a bar. And doesn't.