Firefox portable with open DNS?

I believe so, simply change the DNS settings inside the Firefox Advance tab and look for the DNS settings. I haven’t used Firefox in a while, but i know its in the settings somewhere for that.

“LAN Settings” button on the “Network” tab in the “Advanced” tab of firefox’s settings panel.

Isn’t OpenDNS something you have to set for your internet connection?

Anyway, if you can do it in Firefox you can do it in Firefox Portable :)

I may be wrong but DNS settings are done in the OS not the browser. I use my router to set the DNS to OpenDNS, but that may not be an option for you.