What is the function of a paper clip?

What did people use to serve this function before paper clips existed? What were the problems with those solutions? (Don't forget cost and manufacturing problems as well as problems with use!)

Consider the standard paper clip ... it may be helpful to get one out and use it while you think about this.

• What are at least three ways in which this design does not perform optimally? Describe the problems that result.
• What are at least three other items that are used to connect sheets of paper? (not different design of paper clips - different techniques or objects)? Describe the ways in which these alternatives are optimized -- what do they do better than the standard paper clip does?
• What are at least three ways in which you have used a paper clip that were NOT the uses for which it was designed? What were the formal properties of the paper clip that caused you to use it for those functions?

What reasons can you give for the fact that people continue to use the standard paper clip?