For a lot of our Drupal development projects, developing web site wireframes and information architecture is the first step in the process. A lot of web developers use Microsoft Visio or OmniGraffle as their wireframes tool.
At Appnovation, we have been using a tool called Axure RP for creating wireframes. Axure is a tool that is specifically designed for creating web site wireframes. As a result, all of the tool bar elements are strictly catered towards the web design world. We really enjoy working with the Axure for a number reasons:
1) Drag and Drop Elements
Using Axure, a web designer can easily add form elements and place holders to the page. Since all of the tool bar elements are designed for creating web site wireframes, there is no need to search for the right icon. This is the case for Visio since there are so many different elements available on the tool bar.
2) Export Wireframes as HTML