You can find an archive of selected Clarion newsgroups at www.clarion-software.com.
Tracked groups (showing number of messages as of Feb 8 2012) include:
There is an online forum at http://objectmix.com/clarion/ but it's almost inactive.
The Tek-Tips forum is fairly active and has been in existence for quite a few years.
Forum.ClarionLife.net is a Russian language web forum for Clarion developers.
NetTalk Central is an independent forum for NetTalk users.
http://thinetsolution.com/forum/
Questions and answers related to Thin@ RIA solution for Clarion.