According to freerice.com's totals page (http://freerice.com/totals.html), from October 7th to yesterday, they've donated 3,664,079,450 grains of rice. So using the 29,000 per pound, that's roughly 126,347.5 pounds. So that's an average of 2578.5 pounds a day since the page started.

Here's their FAQ page: http://freerice.com/faq.html