I use this Topeak Survival Wedge bag on each of my bikes.



In addition to the tool kit that comes with it, I also pack in it:

2 CO2 cartridges
2 spare tubes
2 $20 bills
A master link
A tire boot made out of a tyvek mailer
A Presta/Schraeder adapter
Small Swiss Army mini-champ knife (I've used the mini scissors and/or tweezers to remove stuff from a tire)
some zip ties

3-4 Purell handi-wipes


2 pairs of nitrile gloves for messy repairs



and this is the CO2 inflator/pump I use

Genuine Innovations Second Wind Carbon Mini


Is it more than I need? Probably, but this way I'm fairly self-sufficient...