Paper Towel Tubes and Poor Planning

I am gathering supplies for some upcoming team building workshops that I will be doing next month in California. And I am kicking myself for not starting sooner! I need enough paper towel tubes for 20 people to each have one in order to present the "Roll it Along" challenge from Team Challenges, page 200. There is no way I'll go through that many paper towels in less than a month!

As I plan to do more of these presentations and school visits in the future, I'm seriously considering setting up a workbench style collection system (something like this but not so spendy and large) so that I can neatly save all of my bottle caps, bread tabs and cardboard tubes.