WireFraming Tools
http://pencil.evolus.vn/en-US/Home.aspx
http://balsamiq.com/products/mockups
http://www.flairbuilder.com/f
Articles on WireFraming
http://www.smashingmagazine.com/2009/09/01/35-excellent-wireframing-resources/
http://www.onextrapixel.com/2009/07/15/the-importance-of-wireframes-in-web-design-and-9-tools-to-create-wireframes/