Pair programming is more about the two different modes of thought engaged in by the driver and the co-pilot. The driver is thinking tactically: i.e. how do I get this method to do what I want it to do? The co-pilot should be thinking strategically: i.e. how do I keep this class/method from creating side-effects in the rest of the code base. So one person is concerned with the task of synthesis while the other person is concerned with analysis. Modes of thought that cannot be undertaken simulaneously by one person. I suggest you read "Pragmatic Thinking and Learning" for more on this. That senior/junior relationship is nice, but not completely necessary. If you have a "senior" though, the "junior" should be allowed to drive 50% of the time or better.

Net Tuesday is about using the social web for social change. Have you looked into this community for volunteering your newly minted programming talents? If there is not a Net Tuesday in your area, you could always start one: http://www.netsquared.org/share/meetup/start-a-group.