Being that only one GLO on my campus has a house, we have tables set up in the student union during the first two weeks of the semester. It's not just limited to Greeks either, that's why the school calls it the Campus Involvement Fair.

We have display boards, photo albums, and other misc paraphenalia set up and we hand out brochures listing our recruitment events.

Putting up a display board isn't too hard either. You can gather pictures and other random facts about your organization.