For quick/dirty running around type stuff:
+

Attached/clipped to front/back of a baseball cap. Lights and gloves go in the cap when I'm off the bike. The Petzl cost a little bit, about forty bucks, but MAN do I love the little guy. Makes flats, reading street signs, cake. Plus, bright light above brim of cap + dark + beard = NINJA. Or at least as close as any of us will ever get. Good for things not exactly/totally legal. Like the methlab on my BOB. Nothing.

For (non-fixed) commutin's, add:

+

Lit like Vegas.


Keeping the lights on yr head makes a buncha more sense then on the bag, I thinks.... At least for me, I'll change positions pretty readily depending on whatever, but usually keep my head at about the same level. Plus its nice to be able to give the "evil eye" to whatever chumpdick's trying to take a left across my rightofway.