[quote]
Zoo
Wild Animal
Padres Game
Del Mar Fair

Harbor Cruise
Duck Tour
Tidepools – if low tide is really low.
Model Train Museum (best $5 spent in SD)
Kayaking in Mission Bay
Shopping in Tijuana – great horizon broadening
Boogie Boarding
Scripps Aquarium
Fishing
[/quote]

I won’t comment on the usual suspects above. Here are some “alternatives” for the more adventurous type nephew, though you probably need to get a liability waiver from his parents first 🙂

1) Miramar Speed Circuit
http://www.miramarspeedcircuit.com/junior_driving_school.php

2) Solid Rock Gym
http://www.solidrockgym.com/?geographic=SanDiego

3) Mr. Paintball (Escondido)
http://www.mrpaintballusa.com/

On second thoughts, if he/you never been paintballing, now’s probably not the time to learn. It hurts when you get hit (like a few welts that take 3-4 weeks to recover).

4) One comment about the Birch Aquarium (Scripps ). Admission is free the first weekend of every month if you are a Bank of America customer and you show your pictured atm/visa card.
http://promotions.bankofamerica.com/museums/