Using Wireframes in Your Agile User Stories
The Lean/Agile philosophy of "failing fast," continually testing and validating ideas, and working in incremental steps pairs well with the quick, iterative style of wireframing with Balsamiq.
Rather than taking weeks to build a fully-interactive prototype, Balsamiq lets you to create concepts and variations in hours, allowing you to test and validate much more rapidly.
Balsamiq wireframes also fit nicely into agile user stories, where a rough UI sketch can be supplemented by more detailed acceptance criteria.
In an article called "Using Wireframes with Agile User Stories" we propose a process for integrating wireframes into agile user stories that lets them easily adapt to the inevitable changes that agile allows for.