Free software versus shareware
Great paper and always chuffed to see a fellow educator promoting the merits of free software.
I think that it would be valuable to distinguish between shareware and free software. Some of the free software purists could challenge the notion that free software does not necessarily refer to no cost ("free as in beer") tools, but refers to the four essential freedoms aka RMS.
I've always found it useful to refer to the no-cost software as shareware - which is distinct from free software. I know that you're well versed in these subtle distinctions - but when speaking to audiences who may not be familiar with these important differences - its worth making the point.
Hope that you'll be doing your ambassador work for WE <smile>. BTW - I'm very keen to get a range of projects started in WE in the use of free software in education. Perhaps there are folk at the conference who would be keen to help.
Good luck with the presentation and I'm proud to be associated with the free software educators.