Alin, my recommendation is next time post here before you book a trip to California & we can give you heads up!
California is NOT a state you want to be in w/o a car. With a car you could do a lot of the things on your list; without, more difficult, but not impossible.
kef0913 is pretty accurate on his summary, as is ss255. And if you want beach in LA, consider Doubletree in Santa Monica.
Weather can go either way this time of year. It could be cold & chilly (but certainly not UK cold & chilly) & possibly rainy. And it's all relative - we're wearing sweaters out here & folk from colder climes are wearing shorts. But if you wanted consistent warm this time of year, Hawaii is the way to go.
Weather could also be warm & sunny. But if you've got thoughts of Baywatch beaches, that's certainly not happening this time of year. You should see some folk playing volleyball, rollerblading, etc, but unless it's unseasonably warm, only folk on the beaches in bathing suits or by the pool will be the tourists. (you could take a surfing lesson, but you'd definitely need a wetsuit, which they probably would provide - water cold this time of year, but surfers out every day).
Right now think temps are 61F in day; low 50s in the eve.
Even though you're constrained by lack of car, public transportation, group tours (for lack of better word, but getting you to some destinations etc), and possibly limo/driver, should mean you still have a nice stay. Don't despair.
I strongly recommend you contact the concierge via fax or phone at both the Gaslamp Hilton & Bev Hills Hilton, lay out what you want to do, your lack of transport predictament, & ask them to help you figure out what to do on which day, how to get there, etc, etc.
BTW - if you do rent limos, take trains, etc, remember that the GPB kicks the US $$ butt, so things will be relatively cheap for you (think it's $1.70US to 1GPB right now - drat, given my 2 upcoming trips to UK).
Enjoy your stay - our weather on a bad day still beats UK winter weather on a good day! Cheers.
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Sharon
[This message has been edited by SkiAdcock (edited Dec 16, 2003).]