For myself, I wonder why there has been so much focus about world missions that they are forgetting about America (or Canada for the Canadians out there). I'm from the U.S. (in California), and for me, I do not know if world missions is for me. I see so many spiritual needs in our country everyday. What should a Christian do?
I do encourage you to cast your glance overseas: the need is so much greater, just about any way you put it.
Nutrition? A homeless person in L.A. gets more calories of quality food per day than the average person in Calcutta. (See the books by Viv Grigg and Ron Sider in the Urbana bibliography.) Justice? Fifteen million children are sold into sexual slavery each year, primarily in Asia (see Gary Haugen's work in the bibliography). Access to the gospel? There are more bibles, Christian books and radio stations in the North America than we know what to do with. Never in a city in the U.S. are you more than a mile from a church. That is why I encourage you to broaden your horizons: Jesus is doing amazing things in an amazingly desperate world.
By all means, the work in California is very important. Many more of us need to be involved in our cities and villages in North America. But even those of us who are called to the most needy corners of the West need to continually refresh our perspective by learning about what God is doing to restore his Shalom to the world.