This year we shared a stall with green h computers, which turned out to be a great partnership. green h/des had several computers setup running ubuntu that we where able to utilize and provided a nice bring between the two projects.
We had a steady flow of discussions and people curious about software libre, as well as, many who stopped by to state their support of software libre, use of gnu/linux, etc.
The one point we developed during the day was to have ready Matt Lee's Moving to free software pages http://www.fsf.org/working-together/moving as these seem to communicate most easily ways people using proprietary OSs could still make use of software libre. This also lead to a discussion of creating a version of this that could be handed out with additional links (including support) to make our presence at such events have a more long term, effective impact.