Lights!
Check the Lighting & Electronics (something like that) thread. You will find great analysis and recommendations. I have ridden with a helmet mounted light for years and would not go back except if I wanted or needed to make more of a light signature. I am goind to order one of the Cree led flashlights for my helmets. Onec you read about them other expensive helmet lights loose their appeal.
If I get a bar light I will get one of the princton tech or if I splurge a Dinotte or Wilma Led light