I never got around to signing up for the Texas version of the DNC list, but my parents did it and they seemed to like it, despite spending whatever $3 to do it. I tried the national one when it first came out, and the web site had been Slashdotted. Today, it was going very fast, so I registered everything in ten seconds flat.

As a bonus, from the recent Slashdot thread, I learned about SpamGourmet, a convenient service for creating disposable e-mail addresses. It's very simple and appears to work well.