What are fun date ideas in Southern California for a couple in their 20′s?

I’ve lived here so long sometimes I forget how much there is to do around here. Anything from San Diego to LA works. Or, just any date ideas for dates in general (besides dinner and a movie). I’ll take any ideas – fun, romantic, creative, wild, cheap, expensive, whatever.

Here are a couple of ideas for the LA area:

-Spend a day on Catalina Island
-Go to dinner at Yamashiro in Hollywood & watch the sun set over LA (fabulous restaurant if you haven’t been there before)
-Spend an afternoon at the Huntington Gardens in Pasadena
-Spend an afternoon at the Getty Museum or LACMA
-Go to a show at the Hollywood Bowl either by yourselves or with another couple or two
-Take the cheesy boat ride through the Venice canals
-Go to Disneyland

What are some fun date ideas that are also cheap?