"At this point we strongly recommend holding off on giving to this relief/recovery effort. We believe that money isn’t a cure-all, and that there can be such a thing as an 'overfunded' relief effort even in a devastating disaster. We don’t know yet whether that is the case with Japan, but we believe that the next few days will bring valuable information about it (and we will be providing updates in this space). We also believe that waiting a few days will not diminish the impact of your donations."
http://blog.givewell.org/2011/03/11/japan-earthquaketsunami-...
"At this point we strongly recommend holding off on giving to this relief/recovery effort. We believe that money isn’t a cure-all, and that there can be such a thing as an 'overfunded' relief effort even in a devastating disaster. We don’t know yet whether that is the case with Japan, but we believe that the next few days will bring valuable information about it (and we will be providing updates in this space). We also believe that waiting a few days will not diminish the impact of your donations."