A membership is definitely worth it. I'm glad I locked in my lifetime membership at $1,800. Membership rates seem to increase at a greater rate than inflation. One nice feature is the partnership with the America West Club and Northwest WorldClub. As a member, you'll have access to all of the partner airlines branded lounges.

Please see also:

http://www.flyertalk.com/pasttalk/ft...ML/000717.html
http://www.flyertalk.com/pasttalk/ft...ML/000989.html
http://www.flyertalk.com/forum/Forum20/HTML/002991.html
http://www.flyertalk.com/forum/Forum20/HTML/003235.html
http://www.flyertalk.com/forum/Forum20/HTML/002838.html
http://www.flyertalk.com/pasttalk/ft...ML/000542.html
http://www.flyertalk.com/pasttalk/ft...ML/001344.html

Amongst many others.