After searching some cool form widgets I can use I found this post that explains how to setup new beautiful controls for Firefox.
They differ from the original ones found in the original site in order to support CSS button/submit widget override.
I have created the attached script based on instructions from the site.
Just open a Terminal and type:
wget http://braceta.com/system/files/firefox-form-widgets.sh . firefox-form-widgets.sh
The script is currently it was been tested only in Ubuntu Feisty Fawn 7.04 so don't blame me If does not work with other distros/OS's.
New updates to the script (if there will be any) will be noticed here. :)
Happy browsing!