http://www.google.com/ads/preferences/plugin/

update: Google Advertising Opt-Out add-on: updated for Firefox 3.5[unknown prefix: Google Advertising Opt-Out add-on]

Did you know about this? I didn't.  Thanks to some random surfing and an EFF post, I just learned of it.

With this browser plugin you can permanently opt out of the DoubleClick cookie, which is an advertising cookie that Google uses. The plugin lets you keep your opt-out status for this browser even when you clear all cookies.

There are a lot of other Google-related add-ons which do this sort of thing.  I do trust this to work better, but only because it's an open source project.

I checked it out, and I already have to come back to edit this post and report that it's crap.

First, since nobody knows about it nobody discusses it.  The Google Group is practically empty.

I reported a couple of issues:

• It's not compatible with Firefox 3.5.  I'm not able to force it to

be compatible unless I hack the code to do so.<

• Within it is a link to the home page here: http://www.google.com/ads/preferences/plugin/opt-out.html But the home page is now http://www.google.com/ads/preferences/plugin/

Jul 10, 2009 update ∞

The issues which I recently reported have all been fixed in the 1.1 update. So it's now compatible with the new Firefox 3.5 series.

Sweet.