Quasi-wiki wordpress

Hi, I was wondering if there was a plugin to achieve a “write post” or “instant blog” form on a given page, much like the one featured in the Prologue theme.

I know there are other form plugins out there but like the one on the Prologue theme, I’m looking for it to be light, uncluttered and generally fast and easy of use.

Overall, what I’m trying to achieve is a quasi-wiki type website, whereby users would be freely allowed to contribute new articles (though not edit existing ones) – I do realise that tight anti-spam controls would be required. It would function much like any other magazine style site, except the visitors could also be the authors.

Whether this will work is another issue, but really I need some method of allowing visitors (or perhaps limited to registered users) to post easily and instantaneously on a page.

Any suggestions?

Many thanks