I'm going to Japan in the beginning of February 2008. I plan to bring my cell phone, even if it won't work in Japan. (I may need it to and from the American airports.) Once I arrive in Japan, will my cell phone work, and be usable, while in Japan? And also, will I need to use a special adapter to charge my cell phone? (When I went to Europe this past Summer 2007, I did acquire and use a special electrical adapter for the purpose of charging my phone.)

Your American cell phone won't work in Japan. Radio Shack sells an adapter kit for all over the world.