I live in L.A. so there are many great things to do while you're there. You mentioned a lot of malls and beaches. The Grove at Farmer's Market (
www.thegrovela.com) is a great place to go and shop. The historical Farmer's Market is right next door and is a fantastic palce to eat as you have such a great variety to choose from. Century City Shopping Center at Westfield is another great place to shop as it is never crowded and is very calm and relaxing. If you're looking more towards Hollywood, Mann's Chinese theatre and El Capitan are great places to catch a movie. However, like in all areas of L.A., there will be traffic so be sure that you'r not going to tour during rush hour period (4:30-6:00 p.m. is usually traffic-heavy). And no, those celebrity home tours are not hoaxes (at least I don't think :D). If you need more info about what to do in L.A. during your visit, try
www.la.com. Hope this helps!