The Lezyne Twin Speed Drive CO2 chuck epitomizes what a CO2 system should be; tiny, light, and easy to use. While it may seem that something with a high chance of getting lost in your jersey pocket is not a piece of gear you want, that's not the case. (Solution? one of these!) Look at all the space/weight you'll save compared to a hand pump. Plus, blasting a CO2 cartridge into your tube will get you back on the road exactly 5025% faster than using a pump.
The Twin Speed Drive CO2 chuck is made of CNC'd aluminum for a long life of shrugging off abuse. It will accept threaded CO2 cartridges only, but of any size. Presta and schrader valve tubes will fit the Twin Speed Drive.