Here's my reply to a similiar question asked back in Sept. 04:

I am from So Calif & it is usually beautiful here in October.
Hopefully, you will have a car & not get too intimidated by our
freeways. They really aren't all that bad, except in rush hour.
I'll
drive here, but I refuse to drive in Italy or Brazil! We're much
safer drivers... Anyway, if you start in San Diego, it is a beautiful

city - Seaworld and the San Diego Zoo are well worth a visit. Old
Town San Diego, where California was founded is very interesting &
'The Gaslamp Quarter' and has nice restaurants, bars & boutiques;
Seaport Village is a little cheesy, but you're right there & if it's a
beautiful day, a nice walk along the water. Coronado Island is also
nice - the world-famous 'Hotel Del' is there. I've heard about a tour

company that shows you San Diego & also takes you to Tijuana, in
Mexico south of the border, which is fun & eye-opening in itself (I
wouldn't drive yourself if you haven't done it before):


Sandiegotours.us


Up the coast is charming La Jolla & the Scripps Institute. Keep
driving north up the I-5, then cut off to the 'Beach Cities' and
Pacific Coast Highway in San Clemente. This is a cute old surfing
town, next Dana Point has a lovely harbor. Next town inland is San
Juan Capistrano, well worth a visit to it's mission & the Del Rio
District. Although I live in Newport, Laguna BEach is my favorite.
Darling surf/artists town you can stroll the galleries & stores for a
good day. The beach is right there & Main Beach is where it all
happens. (Although Diamond Street beach is my fav - small & scenic.)
Next Corona del Mar, which has some beautiful beaches, coves & cliffs.
If you like gardens, the Sherman Gardens on PCH is very interesting &

beautiful. Then Newport - Fashion Island Shopping Center is fun -
Neiman Marcus & Bloomingdales & fun just to people watch in this
outdoor setting, unusual for a mall. Balboa Island is wonderful &
after walking Marine Avenue, walk along the Boardwalk to the ferry
over to Balboa Peninsula. The Fun Zone is typical old California
beach amusement park & ok to walk through. On the ocean side, is the
huge long beach, starting with the Wedge, a popular (& dangerous) spot
for bodysurfers, then Balboa Pier & then Newport Pier, connected by a
boardwalk. I'm not a huge fan of Huntington, but further north is
Seal Beach, another darling litle beach town.


However, from Newport, I'd head inland to Disneyland & if possible,
Knott's Berry Farm for a taste of old Caifornia. From here, Hollywood

& Universal Studios. For a peaceful & beautiful day, visit the
Huntington Library & Gardens in Pasadena - just spectacular. Drive up

Sunset to Beverly Hills & park & walk Rodeo - always fascinating &
again, amazing people-watching. From here, Santa Monica is a great
town on the beach, Venice Beach is wild & a kick, then to LAX, which
is close by.


If you really have some more time (which you won't after doing all
this in a week!), I highly suggest driving up to Santa Barabara, a
wonderful town - the mission there is well-preserved & a great example
of California's history, State Street is just fabulous with outdoor
cafes, boutiques - lots of fun. Inland is Santa Inez & our S.
California wine country.


Enjoy! Have a great trip! Let me know if you need any more
specifics
& don't let the negative people put you off - it's like saying you
shouldn't go to NYC - ridiculous!