I found a couple of places in San Diego that I really enjoyed and recommend.
For lunch I loved the Fish Tacos at the Tin Fish
http://www.thetinfish.net which is located just outside of the Gaslamp District across the train tracks from the south end of the Convention Center (also near Petco Field). El Mundo's fish tacos are the closest representation I have had here locally.
For breakfast my favorite was Cafe 222
http://www.cafe222.com/. The peanut butter and banana stuffed french toast was excellent. I would place them in the same style category as Lynn's here locally.
Both of these places are within walking distance of the conference center. Hope you enjoy your trip!