In the beginning of the movie when the dude is buying milk at Ralph's he makes out the check for Sept 11th 1991 then glances up and see's George Bush Sr. on the TV talking about invading IRAQ saying "this aggression will not stand"
I don't know if you already knew it, but...
Jeff Bridges wears for a long time in this movie, a T-Shirt representing a baseball player, with chinese (I think!) writings around.
He used to wear the SAME T-Shirt (I think they never washed it) in a previous... more
The fast food restaurant "In & Out Burger" is referenced during the movie. John Goodman once did a commercial for the "In & Out" fast food chain.