The George Washington University Secular Society has a wonderful campaign introducing their group to students on campus.
They took pictures of group members who volunteered to be part of the campaign and put their smiling, happy faces on signs like these:
There are plenty more posters where those came from, too. 13 different students had their pictures taken and several posters of each of them were put up around campus. They are, in some ways, a free billboard campaign showcasing how atheists are all over the place at GW. You might as well talk to them and have a discussion
It’s welcoming, non-confrontational, and a great model for other groups to use.
(Thanks to Julie for the link!)