There's one for developers (which means anyone interested in following and contributing to the development of the Arduino project), one for the whole Arduino community (though I'm not quite sure what we'll use it for), and a bunch for specific cities: Barcelona, London, Madrid, Milano, Malmö, and New York (for people to organize meetups, announce exhibits, etc.).
To request a mailing list for your city or for other suggestions, reply to this post.
Sorry it took so long, we had some problems with our web host.
The forums and mailing lists aren't planned to be cross-posted at the moment, since they serve mostly different purposes: general discussion vs. local events. The mailing lists are all publicly archived though.
i´m neither from netherlands nor from belgium, but actually i´m working in NL. so, if no one is upset by naming it benelux, then you probably name it like that.
So of the users of the Benelux mailing list are using gmail. We have experienced that we always have to rewrite the 'To' field to benelux at arduino dot cc or else a reply will be send only to the originator of the mail you reply to and not the the members of the list.
Do you know if there is a setting in the mailing list that can take care of this?