Apparently you can't buy them anymore, the promotion ran out on February 28, 2011. For confirmation and more information call Disney Guest Services at (714) 781-4636
Disneyland.com is a good place to buy Disneyland tickets, you can also buy them at the kiosks in front of the gates at the Disneyland Resort.
Concrete, Brick & Steel
Adventure Island is not free. You have to buy Disneyland park hopper tickets, then it free. If you buy Disneyland tickets you can only choose one theme park and stay there for the rest of the day.
Online
Yes
No. One Disneyland ticket is access to EVERYTHING inside the resort.
A power brick is a red Lego brick hidden in each level. They unlock extras to buy
You can buy it from Disney store in Disneyland or if there is a Disney store near you there is where you can buy it
in a store
The disney shop or Disneyworld/Disneyland
yes
There are many brick and mortar retailers that also allow customers to purchase electronics online. These brick and mortar retailers are: Best Buy, Walmart, Target, and Kmart.