If anyone's after a cheap route into the wonderful world of dynohubs, www.bicycles.de currently has a bottom-end Shimano hub built into a 700c Rigida rim for the princely sum of EUR 65 (plus, presumably, delivery). It's an H051, which seems to be Tourney level - dunno if anyone's get any more information on drag, efficiency etc. If it's based on the Nexus hubs from four years or so ago it should be OK.