I waited long time for these extension, it seem that time as come: finally you will be able to +1 any page :-)
Here are the extensions to add a Google +1 button to yur Firefox/Chrome toolbar.
Firefox extension 1: http://addons.mozilla.org/en-US/firefox/addon/plus-one-any/ (I prefer this one, but it's a matter of tase :-)
Firefox extension 2: http://addons.mozilla.org/en-US/firefox/addon/plus-one-button/
The Firefox extension add the button to the end of the urlbar.