When God first starting nudging me into being more outspoken in my faith, I found a very ripe field--telemarketers. Whenever I would get a call from one, I was tell them "I will be happy to hear what you have to say, but first I have something I wish to share with you." You have a captive audience; they will either listen or hang up--a win-win situation.
I have had the opportunity to speak with numerous fellow believers and once spent 2 hours talking with a young muslin man from Pakistan. He promised to read the book of John in a Bible someone had given him. We were disconnected and he actually called me back and we talked for another hour.
We also get a lot of door-to-door sales people, another captive audience. Have met some wonder fellow Christians that way also. I've never acutally led anyone to the Lord doing this but am hoping that I am either planting or watering.
Proverbs 18:10
The name of the Lord is a strong tower: the righteous runneth into it, and is safe.