您好,不知您是否飛LA or SFO, 如果是LA, 可以去Disney / Knott Berry Farm, 在San Diego,比較多一些玩意, 可以去Legoland(legoland.com), 全部用Lego 做, 小朋友一定開心, 去參觀航空母艦Midway (Midway Magic.com)及Summarine, San Diego Zoo is the biggest in the World. If you have time, you can cross the border to Mexico.
The most important is you know how to drive in USA. It is easy to drive. You can go to circuit city to buy a GPRS by US$140 or you can rent it from car rental by US$9/day.
In fact you don't need that, just try by error. Only one way to go to San Diego from LA. Or you can print the MapQuest from internet before you go. If you get loss, go to any nearest hotel to ask for direction.