I finally got around to downloading the adblock extension for firefox, when I noticed the latest dev build blocks some elements before they load. As a modem user, this sped up my internet browsing by a thousand percent. I'm fairly sure it will improve broadband also, as I've seen some complain about a site pausing while an ad or script loads.
Adblock 0.5, Development Build 3 You'll also need the pre-made filter list,
Filterset.G:
2007-02-02a.txt (right-click and select "save as," then import it into adblock from within its preferences)
And there's an updater extension, which downloads the latest version of Filterset.G once a week.
Filterset.G Updater