Your original question was about serving your country. While I think the CAP is a very good organization and a helpful part of our aviation community, I don't equate being in the CAP as serving my country. While it is true they have been taking a greater roll in some other government missions in the last decade, they are still primarily a domestic search and rescue organization.
The CAP bureacracy can be very aggravating and it takes a long time to get certified to fly missions. If you can be A) patient, B) persistent, and C) lucky you may get to the point where you do a fair amount of search and rescue as well as "other" flying.
A lot will depend on where you are located. In California we had a very good variety of flying which included Search and Rescue, Organ Transport, Cadet Program, California State OES, Counter Narcotics, and some misc AF VR route surveys.
Breaking into the CAP flying is difficult because it tends to be very "clubish" or "cliquish" with the old farts who try to hog all the flying. Young guys have the most difficulty. You have to find a squadron that will be accepting of you and be points A,B, and C above.
CAP has their fair share of dorks who give the image that iowapilot has, but there are also a very large number of competent, experienced, and dedicated individuals who make the organization worthwhile. I've benefited greatly from my involvement in CAP, not just in that it helped me to learn many things about leadership and flying, but that it has brought me many good friends and contacts in the aviation community. I got my first flight instructor job and my first airline job directly because of CAP contacts.
Again, I wouldn't view CAP as a form of military service, but they did sink two German U-boats during World War II.
Typhoonpilot
26 year CAP member