Is there an online source of ISS coordinates (2d - "point where the
ISS is currently overhead") or the TLE (Two Letter Epheremides)?

Uh, TLE is Two Line Elements (
http://en.wikipedia.org/wiki/Orbital_elements ).

Did you look at http://web.austin.utexas.edu/edcannon/elements.htm ?
That's titled 'Sources of Satellite "Two-Line" Orbital Elements'
and links to some sites which are said to have such things.
I didn't dig far enough to see how closely it matches what you are
looking for...