The cantilever challenge was a week-long activity in Ken Symington's "Design Thinking and Media Communications" class.  

Students had to build the longest and strongest cantilever measured from the desk edge to the end of the cantilever.  Students were given one period to brainstorm ideas, then each day after they built with a different material - starting with newspaper, then moving to straws, and then finally testing their engineering skills with spaghetti. To make things interesting, builders got to use only 1 meter of masking tape per day, and an unlimited supply of the assigned daily material. 

We used a cup hanging over the end and put pennies in it to add weight to test strength and we recorded the weight after it bent 10 cm below the horizon from the desk or collapsed.  We kept a tally of points (10 points for top length, 10 points for top strength) each day and totaled them up the last day for the cantilever grand design champions! 

Here's the newspaper iteration (click for a bigger image)

 Then moving on to straw. Still only using 1 meter of masking tape! 

And then finally spaghetti.