The reason agile works for us is because I can produce something the next day that _forces_ the business people to pay attention. Usually in the first meeting they're carping and whining about wasting time when we (IT) just need to build them something. They don't answer the questions I want answered and think I'm being picky and don't want to do any 'work.' Same old same old.

Next day, I give them a web page to work on and tell them this is the system unless they want to put some more work into it. Then we start talking about each of the buttons and they realize that if there are 3 different possibilities, I NEED ANSWERS FOR ALL 3 SCENARIOS. They have to put work into it.

That's the user insight that _never_ occurs in the waterfall model. For me, the best part of Agile is that it either forces the users to get involved or it lets the developers know no one cares. It's a time-saver either way.