In addition to the Getty Museum and the Huntington Library, I would strongly recommend the Norton Simon Museum in Pasadena. It has a very nice collection of paintings and sculpture and is not as busy as the Getty or the LA County Museum of Art.

In December I walked around the new Walt Disney Concert Hall, which I think is well worth your half-hour or hour, if you're not catching a concert there.

Does anyone have suggestions for hiking or such in the San Gabriel Mountains (for future reference)? Thanks.