Firefox is ridiculously extensible. The only thing capable of being even more ridiculous is the same extensions. You can brand the "About" window with the FC Barcelona football team (W-T-F), you can transform the browser in a file manager (!) and you can know the water level of German rivers (!?), but you can't (or no one is bothering to do a extension for that) show the size of a file in the f******* download dialog. This is one of the things that made me rant the other day about the ludicrous state of Firefox addons, anyone can make the most stupid extension ever and have it hosted in the official site (!?), but when it comes to real needs, you're all alone

OK, after the angry rant, I'll simply say that I have searched back and forth the web and didn't find anything else. If someone finds or codes something, I'll give him/her a cookie

. Either that, or we'll have to wait 'til ¿Firefox 3?
EDIT: I think I've found a solution to use the Opera addon I talked about earlier. There's this extension for Firefox, Launchy, that lets you launch any element in a web page in an external application. What's more, it lets you define your own programs using an XML file, you can find the details at the
extension webpage. Read the FAQ of
the other addon to see how it works with Opera, as you can use the same commandline (I think you won't need any arguments, only the path to the addon), and let me know if it works
