Here is an interesting visual, which expresses pledged support to Haiti in per capita terms. #1 is Canada, by a large margin, followed by some of the Nordic countries.
Per capita the U.S. doesn't do so well (NB: I don't think remittances are counted), with less than half of what Guyana supplies. We're also behind Estonia, Switzerland, and United Arab Emirates, among other countries. The visual is measuring earthquake aid pledged, not all foreign aid.
In absolute terms here is another visual; U.S. is #1. I don't think this is using the same metric as above.
Here's another interesting visual. Relative to per capita gdp, Ghana is the single most significant pledger of aid to Haiti.
For the pointer I thank Rahul Nabar.