I just noticed a post below that got a lot of attention concerning the strobe light. I think it's a good idea and started searching on the web for "bike strobe light". What I found were mostly strobe lights for cars and this very sad story. It appears that a bike commuter was killed even though he was using a strobe light. It just goes to show you that no light or reflector can save you from a careless driver.

driver.http://members.aol.com/CASInc/charlie.html