Those threaded bosses on the rack would allow you all kinds of possibilities, including brackets for flashlights. You could also install a chunk of handlebar w/ a long bolt and washers on both ends and then use a clamp-on battery operated light. V-O also sells a bracket for attaching to those bosses, too:
http://store.velo-orange.com/index.p...t-bracket.html
Lots of lights could be made to fit on to that bracket.
Neal