Fair warning, I've given this a lot of thought.
First I would put between $10,000,000 and $15,000,000 away in either a bank account with a good interest rate, or some other investment that accrues interest and live off of said interest.
With whatever is left over after taxes, probably somewhere around $300 million, I'd start buying companies particularly pharmaceutical and food production and distribution companies. (I'm an Industrial Engineer, production and distribution are kind of what I do)
Every time one of my companies came out with a new product or advancement, which would become the primary goal of any company I purchase, between 10-30% of the new production capacity would be devoted to and provided at no charge to 3rd world countries.
The advances in technology were not brought about by any one person, people, race or creed. And there is no reason these advancements should not be shared. It's is completely unacceptable for people in a situation they did not choose for themselves to be punished for it while others have every means of helping them.
Now naturally this service would cut into the profits of these companies, but between the good publicity and the immense tax write-off this would be sure to bring about, I don't foresee it being that big of a problem. $XXX,000,000+ companies don't bat an eye at spending $1,000,000 if it will make them $10,000,000.
Someone needs to take the first step if any of these problems are to be solved.