How about Lezyne Micro Caddy:
Lezyne Micro Caddy [1-SB-CADDY-V1MCS04] (biketiresdirect.com)?
I have recently (and reluctantly) started to carry a medium (on group rides); it is also available in small, which is a whole inch shorter.
The medium one has separate pockets for tire levers, CO2 cartridge, and multitool so these do not poke a hole in one's spare tube.