Balsamiq Wireframes is a rapid low-fidelity UI wireframing tool that reproduces the experience of sketching on a notepad or whiteboard, but using a computer.
It really forces you to focus on structure and content, avoiding lengthy discussions about colors and details that should come later in the process.
Wireframes is FAST: you will generate more ideas, so you can throw out the bad ones and discover the best solutions.
Balsamiq is the first tool out of your UX toolbox: faster than the sketchbook, and almost as fun to use. It forces you to focus on IA — the rest can come later.
Create templates, masters, and re-usable and customizeable component libraries.
Hundreds of built-in and community-generated UI controls and icons.
Assemble elements with the confidence of knowing they can be implemented.
Wireframe at the speed of thought with Quick Add and many keyboards shortcuts.
Linking lets you generate simple prototypes for demos or usability testing.