Last point that I'll make on this, but from reading the comments about c02 cartirdges, you'd think that everyone who uses them gets stranded by the side of the road every time they get a flat tire. I have never had my CO2 cartirdges fail me on a ride where I was unable to patch my tire. That being said, I have had two pumps break on me in the past & from reading the normal 'Which pump should I buy' threads, I'm not the only one who has had the experience. At least if your CO2 cartridge fails, you have one backup (assuming you bring two). If your pump breaks, you are walking.

I keep an extra co2 cartridge at work just in case I ever have to use one on the way in, so that I still have two on the way home.

Pumps have some advantages, but so do CO2 cartridges. Neither one is THE right choice, it all depends on what best fits your needs.