mostly online
You can find kingdom hearts stuff at Hot Topic. They might be there. That would my first guess on finding them. They also have Girr stiff to for more info.
Yes, it is currently in stores.
Well on long island there is a store called collecters kingdom and they have a lot of kingdom hearts stuff.
There is no such thing as a Kingdom Hearts convention. However, if you want to go to a convention with Kingdom Hearts fans, cosplayers, and other Kingdom Hearts stuff, I would highly recommend that you go to an anime convention. See the related link for more information.
late 2010 or early 2011
Kingdom Hearts 1 and 2 have been out for about 9 years. They are already getting old for shopkeepers and decided to kick them out and put the new versions in.
Riku does lots of things in the kingdom hearts games. Riku tries to gain power and fights his friend sora. and he does more stuff
In Kingdom Hearts II you find the recipe for the Ultimate Weapon in a chest in Twighlight Town by the pods where Donald and Goofy were sleeping.
You can now get the game in most game stores, such as Gamestop. It is Kingdom Hearts Re:Coded. I believe it is for the DS only, but I cant be sure.
The next Kingdom Hearts game is for the DS, called Kingdom Hearts: 358/2 Days. It will focus on Roxas and his time in the orginisation and will be released in the US late september. It was released in Japan on the 30th of May.
Yes, you can buy them from online stores.
They only have at certain book stores.