you could
-remove bar tape and just go with a few pieces of electrical tape to hold any wiring in place
-lighter cages (i'm sure you though of that)
-consider taking the cover off your saddle (or an old one). I know some guys that took the cover off their old SLRs and then drilled the body for more weight savings. the cover doesnt really effect comfort and wont be a factor over a shorter race. i have this chinese carbon thing on my bike and its fine.
Hylix Road Bike Carbon Saddle Seat Fit MTB Riding Ergonomics 91g Touple SL | eBay
-are you running clinchers? veloplugs are reported to be lighter than rim tape. I have them on one of oldest clincher sets....works fine
-i think some water bottles are lighter than others...you should look in to that
-finally my oakley half jackets are boat anchors compared to my smith pivlocks or no sunglasses at all