The above pictures
1. The dynamo mounted on chassis. Dynamo height and 12inch wheel fit together nicely.
2. The headlight. 1W LED +built-in current regulator, housed in a film canister on a simple swivelling mount. Requires 5v. Has a lens, which as the ebay advert described 'makes the bean throw long.'
3. One of he rear lights. 4 columns of 10mm (large) red LED pairs. Takes 10.4v if I remember correctly. Shockingly bright. Comes on at about 4mph, max brightness at 8mph. Voltage is regulated so no chance of burning out. Dynamo in background.
4. On the underside of the chassis, the dynamo feeds a voltage rectifier/smoother (on the right) and a ~10.4v voltage regulator (on the left).
5. The 10.4 v either drives the rear lights directly or can also be fed into the black box with the red display. This box provides regulated 5v output (for ipod charging via USB jack), can also take in a general voltage source (like the solar panel). Also provides the 5v needed for the headlight. The display is a voltage meter, telling you the input voltage or any voltage you desire (e.g. the voltage of rechargeable batteries that you're charging via the dynamo). I made it sound complicated, it isn't.
6. The innards of the voltage meter/regulator/distributor, reveals that I'm not actually an electronics wizard. The voltage meter was bought on ebay, I just added switches etc. It runs off its own battery, so can be used even when there's no sun, and you aren't cycling.

There's also a 6v dynamo on the other wheel. Why? Who knows?