This is actually a reply to a post by Jono Bacon of LugRadio fame, but his comment system doesn't like me, and it's worth repeating to a wider audience.
Free beer and speech: You should never, ever, use the terms free as in beer and free as in speech, as they're opaque to anyone who hasn't read the specific piece[2] by RMS that defines them. For a long time I had them the wrong way around, since it made more sense to me that way - I'd heard of "open source beer"[1], its recipe having a free license (RMS himself uses recipes as examples of Free software), whereas the GFDL (for speech) allows invariant sections[2], and a lot of RMS' writings are freely distributable, but only if unmodified.
[1] Although I'm sure I heard of it before 2005, when Vores Øl was announced.
[2] The first distro I used was Debian, so I'm more influenced by the DFSG than RMS' Free Software Definition.

