I think I disagree with both of you. Some sites need FAQs simply because the issues raised are not under the control of the site owner.
For instance a forum about hardware might see the same questions pop up over and over again and can save on pollution and improve the quality of the answers by creating a FAQ, much more time can be spent on a single answer that way than it ever could be when answering the questions ad-hoc.
Even HN could probably benefit from a FAQ, there are plenty of things that pop up over and over again in 'Ask HN' threads.
And in tribute to the OP it is certainly possible to have a short but strong statement about a subject that you can qualify as a rant and that still comes in under 140 characters.
'Goto considered harmful' would be a nice candidate.
Maybe one of twitters saving graces is that it is actually quite hard to get a good flamewar going in 140 characters ;)
Yes, and often there are two levels of user - those who 'get' what a site is about immediately, and others who need more information. Seperating out detailed descriptions into an FAQ section can lead to a cleaner 'main' site.
