Balsamiq, a software product startup, has released a product called Mockups for Desktop, and also related products (as plugins) for some wiki and other web software (Confluence, JIRA and Twiki).
The products allow you to create software mockups in minutes, and iterate over them with your team.
Balsamiq is a company run by Giacomo Guilizzoni (people call him Peldi).
(*) It actually works for any organization or person, not just for startups :-)
The products have received many good testimonials.
Also, Peldi is offering a free license of Mockups to anyone who either:
- is an open source developer (I got a free license from him for Mockups for Desktop by this route)
- or who is a blogger and writes a blog post about his products.
Since I haven't had a chance to take Mockups for a test drive yet, I'm not writing anything about the features here right now. But since there are many good reviews for the product, and also he has had good sales of them, you may want to check the product out. It also has a free trial during which there are some limitations in the features, like not being able to save files created with it. Those limitations go away when you get a license for it.
Once I try out Mockups, I'll blog more about it.
Vasudev Ram - Dancing Bison Enterprises