Reliant on javascript means I see the sample page in digg's domain. Meaning it doesn't work as one would hope. The daring fireball method at http://daringfireball.net/2009/04/how_to_block_the_diggbar will always work, but doesn't get you out of the page. It just leaves a nasty message instead of the dugg page in the frame.

Nice work making it a plugin though. Will work for most web surfers cuz most are using IE and probably most of the rest have javascript enabled anyway.

There's now a FF extension as well...
https://addons.mozilla.org/en-US/firefox/addon/11422

Gruber is pretty aggressive with his script, as he should be.
I may play with it later.