www.knowtango.com is another wiki for tango events. Personally, I find this one quite easy to use, compared to others (I will post them here as soon as I find the bookmarks again :-P).
Like in any wiki, anyone can view, add, or edit events, and there is an embeded map funtion.
It is an easy, central place to find out about all the tango events happening in the tango-vadio community and everywhere else worldwide. The site is totally free to use with no ads whatsoever, so it's truly meant to be a global resource by and for the tango community.
Diane (firstname.lastname@example.org) is eagerly waiting for your feedback...