Paper Prototyping
The User Advocate: Interactive Prototyping
Part 1: Easy PDF Prototyping
http://www.gotomedia.com/gotoreport/may2005/news_0505_usable1.html
Part 2: Building a PDF Prototype
http://www.gotomedia.com/gotoreport/may2005/news_0505_usable2.html
Visio - the interaction designer's nail gun
http://www.guuui.com/issues/02_03_02.php