Company: 
The zvents team took the wrapper off their social event manager/calendar today. The timing of the announcement couldn’t be better, as Upcoming.org (a competitor) announced its acquisition by Yahoo yesterday.
Ethan Stock posted about the launch on the zvents blog. Key features include best of breed event search, tagging of events, easy blogging and blog/website widgets to promote your event. zvents uses ajax intelligently and the site feels very stable.
Zvents is also opening up a number of APIs to grab their data, encouraging mashups. We applaud them and look forward to developments.
I noticed that tags are in your RSS feeds, but not listed on the actual website pages. You had an “eventful” tag for this entry and I was wondering if you were planning on reviewing Eventful.com (formerly EVDB). Out of many of the new events services, I’ve found it to give the most results, although I haven’t test-drived any of the sites beyond this to see what features one has over the other. (By the way, comment previews would be nice here!)
A review was posted on thelaggard.