If you don't have the material assets to provide maybe a thing of coffee or cookies or what nots . . . then a brochure or flyer like navane said would work well.
It would be great if a potential advisor or some such could be there also . . . Or some prof that has been involved with this organization before?
Make sure the paper you hand them has contact information, links and the major bullets.
Other than that try show a lot of eneergy and enthusiasm. A lot of your success will be your presentation skills.
You are not giving a report, you are sharing an exciting opportunity that will give them great benefits both proffessionally and personally without a lot of disruption on their lives
Oh and not only make the meeting quick. Set the next one up from in the middleof the current meeeting. Never say you'll call them.
Pass around a sign in sheet contact info etc . . .
Good luck.