I spend 5 minutes at www.freerice.com a couple of times a day. It has a little vocabulary game, but that's just a hook - the real point is to show you a page with an advert on it. The revenue from the advert is donated to the United Nations Food Program.
The site started up in October, donating 10 grains of rice per click, and after 7 weeks increased it to 20 grains per click.
So how much is that? Is the resulting contribution remotely significant, or is it just a sop to make rich westerners feel they've "done something" without actually having to put their hands in their pockets?
Well, this thread suggests 28 mg is a reasonable guess at the average weight of a grain of rice. The running total of rice donated by FreeRice currently stands at around 13.2 billion grains, which I calculate to be around 370 metric tonnes; the rate has increased very rapidly though, with over half of that coming in December 2007 - about 200 metric tonnes.
The UN delivered 4 million metric tonnes of food in 2006. Assuming that figure is representative, FreeRice is donating about 1/1600 of the total WFP food budget in its third month of operation.
I'm not sure how many calories a day it takes to keep a starving person alive - searching the Blogoblag mostly finds questions from fat people pretending they want to lose weight - but if it is 1200 kCal/day that's 300g of rice, so the December figure represents enough to continually feed about 22000 people.
That isn't going to make poverty history overnight, but it isn't nothing either. I will watch with interest to see if the contributions continue to grow.