[Dan in Pasadena]

I live in the San Gabriel Valley, in Pasadena. What are you looking to do? Porsche related stuff, general car related stuff or just sightseeing in general? A couple of thoughts:

The Peterson Auto Museum is in L.A. and worth a look if you've never been there. While you're there you can go to Farmer's Market/The Grove. Both nice tourist locations and an easy way to spend the afternoon.

If you want to poke around in general there is the Huntington Library in Arcadia. Old Town in Pasadena is touristy and a nice place to eat/kill an afteroon plus the Rusnak dealership is at the west end of Colorado Blvd and you can go nuts looking at Porsches, Audi's, Bentley's and Jag's there. Hell, just looking at the cars in line for service is a treat there!

Santa Anita racetrack is in Arcadia too.....I'm thinking, thinking. Others will chime in with LOTS of places I have forgotten. Really depends how far you are willing to drive. L.A. traffic, even mid day is awful anymore.