If you have a "loop" on the end of your seatpost bag, you can attatch some cateye lights to that loop using their belt clip option. If you cant find that clip, some of the cheap Bell rear lights have built-in clips that fit those bag loops.

Might be good just because I remeber how hard it is for some drivers to see lights like that...size vs depth perception and all....most drivers will asusme that intense red tiny light might be further off..so it's good to have a large light somewhere


BTW, this is the bag I use, that little reflective bit on the back is the loop I was talking about: http://www.jandd.com/detail.asp?PRODUCT_ID=FTKB