The Internet enables some fairly exotic, acrobatic, new transaction
mechanisms (e.g. complex, contractess multi-payments; trade in virtual
currencies).

Do these new transaction tools enable any new and interesting
business models, especially models for Free Software and Free 
Digital Content enterprises?

I think they do:

  http://www.regexps.com/labnotes/devo-meta-x/view-topic/GnuEconomy/IntroTopic

-t