Rated 5 out of 5 stars

This plugin is in fact great and it does exactly what I was looking for: switching between direct connection to internet and a proxy configuration file depending on where you are. But unfortunately, the explanations are rather obscure... I had to search the internet and I found a very step by step approach to setting that plugin in here:
http://stuffforlife.blogspot.com/2010/01/firefox-automatic-proxy-setting-change.html

Guys keep up the good work and many thanks.

This review is for a previous version of the add-on (2010). 

Many thanks for your review of the MM3-ProxySwitch

We will compare your documentation with our description to optimize these.
Please, if passages which in any case should be changed exist, inform me.