Second Harvest Japan is collecting and delivering food + other necessaries. directly to the affected areas. Send the food to the address at the bottom of the page and (provided it is not past its sell by date, etc) they parcel it up and arrange for it to be delivered to the shelters. Seems much more effective than a cash donation to me. Note: People living outside Japan are apparently limited to cash donations. If you're in Japan you can send items directly to Second Harvest.