Screencast no. 1 shows how to geo-reference a map in YUMA by adding four or more control points.
Screencast no. 3 shows how the context information contained in the Semantic Tags helps to automagically enable multi-language and synonym search.
The videos are meant to accompany my talk at the workshop. I guess without anyone explaning what's going on, their informative value is somewhat limited. (I promise... we'll make a screencast with an audio track. One day ;-)
In the mean time, you might also want to check out the guided video tour of YUMA Map features that Bernhard prepared for the OAC Workshop on Using the OAC Data Model for Shareable Annotations in Chicago last week (but which was too long for my talk slot in The Hague d'oh!)
UPDATE: the slides from my CartoHeritage presentation are on Slideshare!