I had about ~50 PDF documents that I needed to print but the local print shop charges $2 for every file opened. Most of these documents where only 2-3 pages long. Opening the files would cost me $100 and printing the documents would only cost $10.
I found this great post with a Java application that lets you merge multipliable PDF documents in to a single document. Its free, works, and simple. What more could you ask for