A Wiki for Structured Data

The product is the wikiCalc program — a web authoring tool that creates web pages. It is for creating and maintaining web pages that include data this is more than just unformatted prose, such as schedules, lists, and tables. It combines some of the ease of authoring and multi-person edit ability of a wiki with the familiar formatting and data organizing metaphor of a spreadsheet.

Starting November 9, 2005

Hmm, may be useful for a number of projects.  Download it here (link is at the bottom of the page).