So I'm taking the girlfriend and kids out to Sea World this weekend. We're getting up at like 4am saturday morning, and heading out, spending the day at the park, and then looking for something to do near or on the beach Sunday before we come home.

Anybody got any good kid friendly (2 and 4) ideas for me?

Legoland is always a hit with the kiddos.

Check out La Jolla Shores. There's a grassy area for kids, the seals over at the tidepools - it's beautiful. Get there early because it's popular on the weekends, and parking can be difficult. If you're staying closer to Sea World, you can always head over to Belmont Park at Mission Beach. There are rides and lots of stuff for kids to do. You can take a stroll along the boardwalk, stop and have lunch - all just steps from the ocean. Again, get there early.

http://www.belmontpark.com/

There's also balboa park and the san diego zoo.
and don't forget the wild animal park in escondido (go here early though because it's going to be hot this weekend).