R.F.,
One thing we learned as JW's was how to approach strangers and ask some very personal questions (about their beliefs). You can take that idea, and use it by asking people about THEMSELVES. But just don't ask really personal questions, just ones you think will get the ball rolling. if you can get someone talking about themself (and shut up and listen intently), then they may begin to think you are a great conversationalist.
The only difference is that you aren't there to convince them they're wrong, you just want to have a conversation.
You don't need to be the life of any party. Just show a little interest in one or two people. Give them a chance, and many people will enjoy your company.