Couple of things I carry that aren't mentioned above:
Spare fairing bolt and well nut
Bungee cord & some small cotton rope
Small squashed roll of electrical tape
Pocket tire plugger from Stop & Go
http://faq.ninja250.org/wiki/What_ca...on_the_road%3F
CO2 cartridges & filler for refilling after the flat (plus 6 12g cartridges)
http://www.aerostich.com/ultraflate-tire-inflator.html
Available from most bicycle shops. You'll want to carry lots of cartridges if you go this route. I decided to use this instead of a pocket compressor since I already had a spare filler and cartridges them on hand from my bicycle.
Between the two flat-tire items, they're just too big to reasonably fit in the tail in one package with my packing method. So, I double bagged them and zip-tied it under the battery box VERY securely after removing the airbox. Pictures of the final placement forthcoming in the (later) morning.
Agree the screwdriver sucks hard. Hadn't thought about replacing it though... Need to replace the combination wrenches too; previous owner seems to have filched them.
Good ideas here folks, thanks for sharing!