Slip Streaming on the road

Alex Having said that, fixie riders tend not to do it, either because they do not know how to, or because one rarely rides really long distances on fixed.

Don't know how? Presumably you're not talking about anyone who learned to ride fixed at Herne Hill, in which case drafting is about all they do know...!

I occasionally draft people if they're fast and competent and I don't think they'll mind, but that sort of rider is fairly rare in London. A friend of mine got shouted at by a very angry commuter after drafting them for half a mile or so.