I've found a way to customize an icon or create a new one in the bookmarks toolbar for FF4.

(snip) I posted the details, but I'm now seeing that there needs to be some major changes. I've removed what I had and I'll try to fix it and post itb later.

jo-ro I would love to find out how to be able to edit Favicons. I hope you find a solution soon.

Here's how to modify your toolbar icons icons in 4. It's not elegant, and it requires that you have an earlier version of FF3 somewhere, but it does work.

Since FF3 and FF4 both use the same bookmarks.html file (where icon information is stored), you do what you want with FaviconPicker in a version that works with it (before 3.6.11) and then export the bookmarks.html file somewhere, where you can then import it in 4.

I've been able to do this with an old laptop that has FaviconPicker working wth FF3, but you could up set both FF3 and FF4 on the same machine, using the instructions in [[Install Firefox 4 Beta alongside Firefox 3.6?|http://superuser.com/questions/160986/install-firefox-4-beta-alongside-firefox-3-6]]

This doesn't work if you use Firefox Portable 4. The way the portable version reads the bookmarks.html has some differences. (I wasted a lot of time finding this out.)

Before you start this project, make a backup (export to a different folder) of your bookmarks.html file in 4, just in case...

Well .. *sighs* .. I was thinking it might come to this. Neither Mozilla nor the creator of FavIconPicker [or an understudy] has yet come forward with a FF 4 solution and may not for some time yet, if it all.

So! We do it this way and get the same result, only a little bit longer in the getting it done department.

Thanks to Everyone!  :-)

But the first time you use the bookmark to go to the site that has a different favicon than the one you assigned , the favicon is overrode by the site's. Did you find a way to overcome this?