The Capital PC User Group, Inc.
The link is outdated: http://www.cpcug.org/
The site is possibly not maintained. This is the third largest PC-based user group in the United States, with more than 3,000 members. It has 27 special interest groups (SIG) including one on Statistics (http://www.cpcug.org/user/sigstat/). For instance, see Statistical Software Support and Information (http://www.cpcug.org/user/sigstat/statsoft.htm), Forecasting Links (http://www.cpcug.org/user/sigstat/forecast.htm), Statistical Data Sources (http://www.cpcug.org/user/sigstat/statdata.htm).
Link added: June 19, 2015