Takis referred me to a Google tech talk about git by Linus Torvalds.

[youtube:http://www.youtube.com/watch?v=4XpnKHJAok8]

Although I am more of a bzr advocate (for one because it’s easier to use, and fast enough for me), he gives a good explanation for the need for distributed revision control (which both bzr and git belong to).

Well worth a look.