I am presenting and promoting open source software at various locations. It is much more impressive to show the power of KDE/Linux when you have some content with you; Amarok rocking the booth is much more attracting than a plain KDE Plasma Desktop (the plain Plasma Desktop is attracting anyway but it could be enriched :-) ). Interested people could play around by themselves if they find some data on the demo machine. You can't do much expect moving Dolphin windows with a blank system (unfortunately most live CDs don't provide content). We wanted to change that. So I submitted a couple of tasks during the Google Code in project.
Now
* we have cc music (which works with Amarok's Wikipedia, lyrics and CD cover downloads features,
* we have HQ blender videos (like sintel) to show multimedia power (moving pictures are always attracting),
* we have documents in ODF- and MS-formats to show the import/export capabilities,
* we have pictures for your favorite photo-management software (like digiKam or Gwenview).
The next step would be to create compressed archives to make it possible to download the whole packages but I haven't found a good place to put them.
You can download the content onto your promo machine (e.g. I put it into my demo-user home directory) or integrate the content onto live CDs (or more likely DVDs when talking about videos).
With Suse Studio you can create a live CD/DVD/USB-Stick within a couple of minutes. You can choose the applications you want to have included and you can upload all the demo content.
Perhaps the creators of live CDs find some space on their media to include at least parts of that demo content. IMHO it would significantly increase the experience for a our users / testers.