Joe Thorn at the Sub*Text blog on ministry in suburbia has a great post on how to have authentic conversations leading to the Gospel - see Gospel Connections in Suburbia : subtext. Some excerpts:
8 topics that can naturally connect to the Christian faith.
1. Corruption, evil and sin......Conversations about corruption and evil are pretty common in my experience. Murderer’s go unpunished, children are exploited, racism continues on in more polite forms, mayors are busted smoking crack, etc. These conversations can naturally connect to the biblical issues of justice, judgment, forgiveness and redemption....
2. Community.... Conversations about community naturally lend themselves to the reality that we are made for community, that God himself dwells in eternal community (Father, Son and Holy Spirit), and that a central component of God’s saving work is the establishment of a community, a family, made up of every tribe, tongue and nation.
3. Politics....Political discussions are a great opportunity to relate the second greatest commandment (love for neighbor) to the management of power.
4. Environment..... This too is an easy topic to connect to the Christian faith. God as creator and the cultural mandate in Genesis can make the leap shorter.
5. War. ....“War is a terrible thing, but if we are going to seek to the good of others and protect the innocent, sometimes war is an unfortunate necessity. That doesn’t make the issue easy. In fact it makes it more difficult. And my concern for justice is rooted in God’s love of it.…
6. Family....It is a shared interest between our church and culture, so this point of connection can serve as an opportunity to move right into the Christian faith - and even the gospel itself as we emphasize grace-based parenting that aims at the heart, not just behavior.
7. Church....Anytime I find out someone goes to church we have a great discussion about their faith, the differences between Roman Catholicism and Evangelicalism, the words of Christ vs church/religion in general. Obviously, once this conversation is underway there is virtually no leap to make.
8. Art/pop-culture. Everyone watches television, goes to the movies and listens to music. Many of the forms of art in pop-culture provide excellent entry points to get to the greater themes that the gospel addresses. This is often an easy connecting point that gets to the issues of sin, justice, forgiveness, redemption, etc.
I have done some editing (shown with "...") so you should follow the link and read the whole thing. It's really thought provoking and well done.