There are a lot of fun things to do in San Diego for senior citizens. In addition to the usual tourist destinations, like the San Diego Zoo (senior discount on their Best Value admission package), and Balboa Park's museums and environment, there are many places that might be more of interest to senior tourists.
Because of San Diego's fabulous weather, there are many resort hotels that have golf courses, especially in north county. Seniors looking for a good view might enjoy short hikes around Torrey Pines State Park or Cabrillo National Monument, both on the coast, with ocean views (Cabrillo also has a nice view of downtown). For the history buff, check out Old Town State Historic Park to learn about early California, or see the Maritime Museum (on San Diego Bay) or the USS Midway aircraft carrier museum. For shopping opportunities, Seaport Village (on the Bay) has some unique shops, and downtown La Jolla has ritzy shopping, while serious shoppers might enjoy the factory outlets at Viejas casino, or San Ysidro or Carlsbad. For nice dining, check out Little Italy or North Park or La Jolla.
For the mobility impaired - the San Diego transit system (trolley and bus) is fully ADA accessible, although not always easy to use.
A good site for things to do in San Diego and San Diego hotels is:
http://www.san-diego-vacation-attractions-tours.us/
A few additional San Diego related websites are:
http://www.brokerforyou.com
http://www.medical-research-study-directory.info/san-diego-medical-research-study.htm
http://www.san-diego-plastic-surgery-cosmetic-surgery-doctors.us/
http://www.lasik-surgery-san-diego.info
http://www.sandiegolawyerforyou.com/
http://www.san-diego-dentist.us/
http://www.downtown-san-diego-real-estate.com/
http://www.san-diego-for-sale-by-owner.com/
http://www.la-jolla-ca-del-mar-san-diego-real-estate-encinitas-california.us/