Joined: Jan 2009
Posts: 44,193
Likes: 6,428
From: New York, NY, and High Falls, NY, USA
Bikes: 1962 Rudge Sports, 1971 Raleigh Super Course, 1971 Raleigh Pro Track, 1974 Raleigh International, 1975 Viscount Fixie, 1982 McLean, 1996 Lemond (Ti), 2002 Burley Zydeco tandem
Funny stuff, [MENTION=47248]andychrist[/MENTION]! But fair warnings, too.
As a very alternative approach, it is also possible to build a cheap dynamo system. I've bought a few old sidewall dynamos off ebay, and they work fine. There are some inexpensive headlights that are built to run on dynamo power. I bought a B&M old model whose main emitter is halogen, and it has a standlight LED. The light is not amazing, but it was cheap, and it's more than adequate for occasional use. The light bolts onto the bike, of course, and so does the dynamo.
This is far from perfect, but if cheap is what you need, it works, and it is immensely reliable. Obviously, one downside is that when you engage the dynamo, there are noticeable drag and noise.