Equal wages/prices for all regardless of geography, brought on by a single world currency and the internet? That would solve world hunger (which is a money issue, not supply issue).
edit: Awesome. It's getting downvoted here too? What the hell is wrong with the concept?
edit 2: Oh I was completely blind to the obvious here...I mean equal wages in terms of task (not geography). A McDonalds worker should make the same here or in another country (assuming McD's was charging the same for burgers too). Software developers who contract online are approaching this equality. I am not suggesting communism or some sort of set rate for work, individual productivity is really important.