Adobe Acrobat is commonly used for creating documents distributed off the web, and for a host of other uses. A couple of years back we traded in our Acrobat Reader, for a version of Adobe Acrobat professional. At the time I was unconvinced that the switch would be worth it. We already had a utility from another program that could print documents to .pdf. The ability to create, assemble and add advanced features has definitely been worth while.
With advanced features of the new Acrobat pro you can imbed various types of data, embed audio commentaries that can be played while viewing, and a host of other features. It has made Acrobat a staple of our digital workflow and email correspondence.
I especially like the slideshow feature. By changing the view to full screen you can flip through a .pdf document just like using PowerPoint.
Hardware Zone article on Acrobat 7