asdGB (Automatically set Default Gnome Browser) is a simple bash script that runs in background, checks for opened browsers and sets, depending on your preferences, the default browser of Gnome. This means that when you got just one browser opened your http:// links will be always opened inside that browser, instead of looking for the default one.
As I said the script is quite simple, it just checks for running processes from a list of known browsers, then choose the one you prefer from your configuration.
Yep you can use it and downloading it from here.
Can I [II part]?
Yep you can do everything you want with this script. It’s under GPL v3 licence. This means, do whatever you want but share it as I did.
Installation: Download it from previous link, unpack the bz2, put in on your preferred directory
Running: ./asdGB.sh -h