I don't know about you, but I kinda like installing random products from the Collective to see what they do.  (On my development server of course, never on a live production server!)

Tonight I played a bit with ATRatings, which provides simple, snazzy content ratings (1-5 stars) and hit counting.  This is one of those "online community" features that isn't essential for every site, but can really help a site that wants to guide users to its most popular content. 

What's particularly cool (to me) about ATRatings is that it marries some heavy duty math from Dr. Geoff Davis with some slick javascript UI bits from  Junyong Pan.   Crunching the numbers to get accurate average ratings and hit rates is tougher than it first seems, and so is providing a nice UI that makes rating stuff quick and painless.  (It looks to have been inspired by Netflix's very smooth 1-5 star movie rating tool.)

One minor suggestion: currently, enabling ratings on a folder and choosing which content types can be rated requires going through the ZMI, but it would be great to push these into a folder tab and Plone Control Panel configlet (respectively) so that average site administrators can control the basic switches of ATRatings without having to delve into the sometimes-intimidating ZMI.

ATRatings is a great example of the kind of simple, useful community-oriented features that oughta be bundled with future releases of Plone (but be disabled by default!).  My compliments to the chef(s).

NB: The current release on Plone.org, tagged version 0.2, doesn't seem to work as well as the latest checkout from SVN trunk.  I hope that Pan (or Geoff) will consider tagging a new release soon.