Prospect St in La Jolla has a lot of shopping, restaurants, day spas, galleries and more! There is so much here that I haven't seen everything. There are little nooks and alleyways filled with stores.
There are several galleries- don't miss Peter Lik's gallery- http://www.lik.com/. He takes incredible photographic images and then uses a special developing process that creates an illusion that there is light behind the photo. It's amazing and well worth the trip just to check out his gallery, and then you can find something to eat or drink or walk down to the cove.
Another store I enjoy is The Turquoise Lady has some gorgeous semi-previous stone jewelry, It is very easy to spend some time in there admiring all the pieces.