Getting to and from ONT ain't pretty but it can be done:
Omnitrans bus 61 passes by it:
http://www.omnitrans.org/routes/list/route61.shtml
and 61 also serves the Fontana Metrolink Station (on the San Bernardino line).
The nearest Metrolink Station is East Ontario, but you'll have to take a cab there.
http://www.omnitrans.org/routes/metrolink.shtml
I always laugh when I hear LAWA promoting ONT on the radio; they have done nothing to create an easy link to the two passenger rail lines that pass right by the airport.
