The History of Interactive Television
http://technology.guardian.co.uk/online/story/0,3605,468542,00.html
http://www.idigitalsales.co.uk/interactiveadvertising/history.cfm
http://filebox.vt.edu/users/rochandl/Network/history.html
http://tvinteractiva.no.sapo.pt/mba_docs/mba_02.html
http://www.rogertowne.com/InteractiveTV.htm
http://www.itvalliance.org
(further down the webpage)
http://www.pbs.org/crashcourse
http://inventors.about.com/library/inventors/bl_television_timeline.htm
The Road to Convergence: Network Transformation and IP