AdWords API APIlity Forum - join
This group is intended for PHP developers working with the AdWords API. All PHP-related questions should be posted here. This includes questions concerning the APIlity PHP Library (http://google-apility.sourceforge.net/).
Low activity, 699 members

Adword-User-Group - join
User group (UG) for professional users of Google Adwords.
Low activity, 1007 members

SEM 2.0 - join
Intermediate to advanced search engine marketing discussion. Members are typically dedicated to helping one another, so applications that appear to be from prospective spammers will be deleted. If you join, please contribute regularly if you have ideas that can help others!
Low activity, 1611 members