Ed, in my work I have attended quite a few seminars. Sometimes the certificates are in the handout books in the back. Sometimes the certificates are on the back table as you leave. Some even go as far as mailing it to you. No matter what that is all they are ... a piece of paper and mean absolutely nothing ... though I do take pride in the Dale Carnegie 12 week course I took and was awarded by my class members Achievement Award and Personal Progress Award as these were not handed out to everybody and the class nominated you for them.

And like you have pointed out you can download or send away for many of these which further dilutes anything prestigious about awards. Unless it is done by your peers and actually means something and you don't flaunt it or stick it out for everybody to see, then it is meaningless.