Adblock, NoScript, etc. are not what this guy is looking for.
He's looking for a way to block the Ad's that are played before the SWF videos or games load and play, within the SWF itself. You know, like on Metacafe where sometimes it has that little "continue to video" link at the bottom you can use to skip past the ad.
Adblock and NoScript just block the whole .swf but if you do so you also block the content.
I've been able to block JUST the ad portion of a loading .swf but I don't know of any addons or other software that will do it automatically. What's involved is placing the ad host into your "hosts" file and redirecting it's IP to 127.0.0.1.
The SWF that loaded the ad will generally detect that the host is not available or not responding, and just go ahead and load up the media you intended to play in the first place.
As I said, I've done this successfully.. but it's a pain to set up right now and it would be awesome if one of you programmer freaks out there created an add-on which does this automatically. The challenges involved are as follows:
1. Detect the URL/host of the ad content. This can be pretty tricky since and is usually only identifiable when the ad is playing.
2. Put the ad content host in the hosts file, redirected so it's unreachable.. unless there's a way to redirect/block it with firefox itself. Remember this is a .swf so adobe player is more-or-less running outside of firefox.
3. Firewalls and intrusion detection programs are gonna tweek out that you're fiddling with the hosts file.
Good luck! Please post if anyone knows of addon's that do something like this!!