for man kind.

Prompt: "If you could invent one thing to help man kind what would it be?"

There are so many issues and situations in this day and age that deserve our attention. Should we stop global warming first, how about the aids epidemic... both are issues which will inevitably harm us. Though, important I am going to go in another direction. I would work towards ending world hunger. Every country has starving children and adults. With the ability to feed themselves, I feel we could rid ourselves of many problems.
1. Reduce violence over food supply
2. Get rid of the militias hoarding the food in Africa

I would invent a new strand of rice, that is self multiplying and purifying.
There for you could drop one grain of rice into a pot and it would make enough
for you family and it would purify the cooking water.

Therefore, we would have more food and safer water.
The malaria epidemic would definitely become less of a risk
and so would the thousands of other diseases spread by water born germs.

Well there you go... you've got the idea now invent it already...