Don't listen to users. Watch what people actually do. Do not believe what people say they do. Definitely don't believe what people predict they may do in the future.
Mock up your design ideas on a few screens before you invest the resources on detailed design and implementation. Test each design with 5 users. And run many rounds of user testing. The cheaper each round, the more rounds you can fit within your budget, and the more you'll learn about user needs.
Some people complain because cheap and fast usability studies don't teach you everything about a design. But that's irrelevant. Yes, a bigger study would yield more results, but you'd get those results too late to influence the big design decisions. Also, the second or third rounds of testing will reveal anything you might have missed in the first, fast study.
V. useit.com.
