The BBC has done a deal with MSN to make various archive Dr Who stories available to watch online.

Adventures from each of the seven original doctors are promised; The Web Planet (all six episodes) is already up on the MSN UK website.

Further stories are to be uploaded one per week (I think), and are scheduled to be The Tomb of the Cybermen, Planet of the Spiders, The Talons of Weng-Chiang, The Caves of Androzani, The Mark of the Rani and Survival.

I’m not sure any of the more recent adventures have been licenced, or how long the archive ones will stay up online.