Dreaming of relevance or maybe going viral - just how do we change the world?

Over the weekend I was thinking about the dream of being relevant or having impact. Over a late lunch today with a friend who has worked in international emergency work and is now in development communication we talked in a bit more depth about various aspects of having an impact. How emergency aid workers are trained to not try and resolve anything other than the immediate problem - food shelter and water for today. Impact is in the here and now, it's about today and not about changing things for ever.
How do we change the world, have impact, touch others with a message that we passionately believe is important? Is celebrity for an idea or an individual the answer - going viral on You Tube the only mark of success? (Watching the media circus of recent months around Susan Boyle has hardly been edifying.)
At the beginning of my year of theological studies in the former GDR in 1989 our course tutor read from and encouraged us to read further Manfred Josuttis' Der Traum des Theologen (published in 1988). It begins with a preacher dreaming about preaching to a packed church, condemning apartheid and the people applauding - a real dream of having impact or resonance. I can still remember the woman next to me muttering under her breath "this is a very macho dream of adulation". Later that autumn there were a few brief weeks when the churches were packed, when the words of many pastors and church people in the GDR were listened to and applauded. Then the Berlin wall came down and the churches gradually emptied again.
The desire to have a big impact is no doubt very human - as is the desire to say that the small impact we are having is more significant than it really is. This need to live the dream of relevance often blinds us to the reality of needing to get on with humble, incarnational work - writing, talking, listening, studying. The lasting relevance of what we do will be in the quality of our message, the integrity of our vision and in the relationships we build, and not necessarily in the brilliance of our fine preaching or super-packaged gimmicks.