I would like to add to your list:

a frame pump and/or some compressed gas (CO2) cylinderettes and the mechanism to use them
a patch kit
an underseat bag large enough to carry two spare tubes a set of tire levers, you CO2 kit, you patch kit and a small pocket knife along with your tool kit Hex wrenches and assorted screw drivers,(cranbrothers does a nice small one about the size of a pack of cigarettes that has 6 hex wrenches in assorted size, 5 screwdrivers in assorted sizes and a chain break which I know how to use been have been lucky enough not to have had to.)

Regardinng all of the above bear in mind that I usually ride solo and rarely in a group plus I am usually away out in the country, beyond immediate help or rescue, so I have had to learn to be a self emergency mechanic. However even if you ride in a group, you should never be without spare tubes and inflation devices of some sort. That's just common sense and courtesy. You may not know how to do it all right away but at least you be equipped so that someone can help you.

Happy riding.



two bottle holders
two bottles with d\wide mouths so that you can get ice cubes in ( insulated or not your coice) I ride with one insulated and frozen in the summer so that it is at least thawed and coolish by the time I need it.)