Definitely go walk around the Hotel Del Coronado (when you're in the San Diego area, it's the hotel *everyone* knows about!) and the beach there is really nice (if they still do it, the Navy guys run the beach along there at times during the day)
Sea World is pretty overpriced, but if you ever think you're going to come back to San Diego this same year, you can buy the Fun Card which is approximately $5 more than the one-day admission price.
The Zoo is always fun (especially with the relatively new Baby Panda) as well as the Wild Animal Park (I think they have special packages for a reduced price to get to both places)
If you want to check out some of the "smaller" towns in San Diego, definitely go to Julian - a small historical mining town that serves the best pie around!
The Gaslamp Quarter has a lot of places to check out and investigate, and Horton Plaza is right in the middle of it all (as well as the new baseball park that opened this past year!)
Maybe if you're in the area for a little while, we can get a So Cal GC get-together planned?
