By any means possible.

As a friend pointed out, The Church of Jesus Christ of Latter-day Saints has an extensive humanitarian program. There are a couple of ways you can donate to this fund:

1. On your tithing slip, in the 'other' box, you can list your amount and put Japan Relief Fund to specify where you want it to go. Or just put Humanitarian aid and it will go into the general fund that helps all LDS relief efforts.

2. Visit THIS website to donate online.