Apple has official made an iTunes page to help those who suffered from natural disasters such as Tsunami and Earthquake in Japan. All of yours donation will directly go to American Red Cross. The main aim for creating this page seems to help those who actually want to donate through some trusted sites. The donation starts from $5.00 and end up to $200. Here is some description from the iTunes page :
Your gift to the American Red Cross will support our disaster relief efforts to help those affected by the earthquake in Japan and tsunami throught the Pacific.
Apple sure has decided to go beyond the call of duty to help Japan and it shows their commitment in doing business with a real heart.
Donate from here