I go back and forth on this issue.
Depending on how lazy I am on any given day. ;)
On the one hand, I have to honestly say I've never received any useful information from users by using questionnaires. The "best practice" I've settled on is to mock-up a few pages (often drawn from competitors' websites), then sit down one-on-one with selected users from each department involved, walk through the pages, get their ooh's and ugh's. In my experience users don't know jack until you think it up and show it to them. They have no concept of the Possible when it comes to interfaces or functionality, let alone the Reasonable.
On the other hand, I can be *really* lazy when I want to... :P
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Many fears are born of stupidity and ignorance -
Which you should be feeding with rumour and generalisation.
BOfH, 2002 "Episode" 10