We've put together this list of guidelines for speakers for both our events, but also as a basis for other people running free software events.
Remember, this is a free software conference. When talking about software that the user can share, modify and distribute, please call it Free Software or FLOSS, instead of Open Source or OSS.
When talking about terms that hurt our community, such as "Intellectual Property", consider alternative terms, or simply referring to these terms as quotations, ie say "quote Intellectual Property unquote".
Presenters should, where possible, deliver any slides in advance (to campaigns@fsf.org) using OpenDocument presentation format. We'll provide laptops running fully-free GNU/Linux distributions for presenters to use.
Any slides which cannot be sent in advance should be presented using a free software operating system such as GNU/Linux.
If you aren't sure where to start with free software applications for presentations, OpenOffice.org, KPresent, LaTeX and S5 are all great ways to do smart looking presentations using free software.
Finally, when you're referring to an operating system with a Linux kernel, don't be afraid to call it GNU/Linux -- we're all friends here, and many of us work on building the GNU OS.