3) Last but not least.... we could join efforts and write an Upp book. It could be done on an opensource tool like Openoffice Word, for example. It could contain the docs, some step by step guides, some guided samples and so on. I'd be glad to partecipate, but we should be at least 4-5 people on it, it's a big effort.
My take is that book should be based on examples. Tutorials, e.g.:
were meant as sort of basis for such book. reference examples could be documented with T++ (we can devise some simple standard topic name for that) - later we would just gather these to form a 'book'.