I'm going to go ahead and be the one to say something a little bit the other way - when I started biking, I bought pumps, tubes, patch kits, etc, because I'd get a flat at least once or twice every year.

But then they came out with puncture resistant tires. And - while I still carry a pump, a spare tube, and a patch kit - I've only had 2 flats, and those were on the inside of the wheel with new tubes (bad tube I guess). (And this is also why I don't carry CO2 - I almost never use it, and when I would I'd just end up forgetting to replace the empty cannister at the end of the ride.)

I really thought the Topeak Road Morph and the other one here in the thread were cool, and I own the Road Morph, but - with flat resistant tires, I just don't think they're worth the additional bulk vs a traditional and smaller pump that can mount under the water bottle cage. For a commuter bike, I also prefer a pump small enough to keep in one main bag on the back so I can just take the bag off the bike when going inside and not have to worry about carrying anything else with me. And unless you actually ride with a pannier, the full size road morph is just to big (plus it's difficult to mount on the frame).

The **Mini** Morph isn't bad for size, really all you need for a pump is something that will get enough air in your tire to get you home - especially if your commute is only 4 miles.

(There are exceptions - if you store your bike inside at work, if you are carrying a pannier, etc etc, this is just what I've found for my setup).