shortest amount of keystrokes to see URL in an external browser

[jidanni]

Let's say you are viewing or editing file.txt and there is a URL
http://example.org/ that you would like to visit in an external browser.
Well with FFAP installed, C-x C-f upon it would get you there in an
internal browser, but if one wants to see it in an external browser, a
lot more work will be involved. C-u C-x C-f of course does something
different. Note I am talking about .txt files, and not mail messages
like these, where one could use M runs the command browse-url-firefox
etc. At least with my http://jidanni.org/comp/configuration/ .