I wrote another greasemonkey userscript: yahoo groups interstitial ad skipper. Ok, "skipper" is not quite right, but it immediately moves on to the actual message. If you've used the web interface to Yahoo Groups, you've noticed it occasionally inserts an advertisement before you can view the message. Adblock does a fine job of removing the ad itself, but you're left with an essentially blank interstitial page. This userscript automatically "clicks" on the Continue to message link. This is especially useful when opening several messages into tabs in the background.