Now I find that Fred Clark, author of Slacktivist, has posted his own suggestions for effective evangelism. They aren't making the same points - he's working from the more general topic of how to evangelize effectively - but in some ways I think he does a much better job of answering the question positively than I managed in my own essays.
On a related note, Steve Sanchez (over at Stone The Preacher), mentions a would-be evangelist who tried to give Lady Gaga a Bible tract. He notes, "As Christians, we ought be the most gracious, most polite, most tactful of people when we share our faith. Sadly, not everyone feels or acts the same way. Our team sees this man quite often when we go out to big events—and we stay on the other side of the street so as not to be associated with his unloving methods." While I appreciate the sentiment, as far as I can tell Pastor Steve and his group are also there to hand out Bible tracts - so the fact that they're on the far side of the street (and presumably smiling at the time) doesn't do much to distinguish them from the fellow he criticizes. Handing out tracts is a fundamentally unfriendly means of evangelism. Mote, meet beam.
Pastor Steve also explains, in his post on how he got started evangelizing, the following:
One point stuck with me: In the New Year we should evangelize more.I'm sure Pastor Steve would disagree, but this seems to me like a radically misguided approach. It's precisely the sort of decision that leads people to extreme (and extremely ineffective) means of evangelism, usually the ones that require you to accost innocent strangers in public settings.
How many times have you heard that as a Christian? Easily, a million times. And what did you do about it? Same thing I did probably: you listened, nodded your head (probably pursing your lips as you did), made a half-hearted commitment to start sharing your faith, somehow, somewhere, but ultimately let it pass by the wayside, along with your other vows, like reading through the Bible in a year, or losing twenty pounds.
That morning, however, I chose to do something about it. I sat in my chair at church (we don’t have pews), and said to myself, “I’m going to share my faith everyday.”
So how is it misguided? I mean, sharing the Gospel is a Good Thing, right?
Glad you asked. Here's the thing that came to me while I was reading this: Are you living your faith? Do you interact with people? Then you're sharing the Gospel. Preaching at people you don't know (whether with words or with tracts) isn't going above and beyond; it's missing the point.
By all means, preach the Gospel. But only use words if necessary.
 From the Latin root, Radix, "at the root."