So here are three options for pumps you carry with you on a ride. Under each picture is a caption with a link to our website for more information.
These are disposable cartridges that blow a stream of carbon dioxide to fill up a tube to about 90 psi.
|Planet Bike Airship CO2 pump|
They are convenient and quick. The down side is that they are bulky, heavy, and usually don't fill up the tire all the way. You can use one of the CO2 pumps like the Airship to modulate the amount of CO2 going into the tire.
|Portland Design Works Shiny Object CO2 inflator|
You can also save space and weight by simply running with just the inflator head. These have some level of modulation.
|Planet Bike Red Zeppelin CO2 inflator|
I use this Planet Bike inflator since it's simple and lightweight. You can recycle these cartridges in the metal bin, along with any soup or vegetable can.
These are light-weight and simple to use. The downside is that you need to pump a lot to get enough air in the tire.
|Planet Bike Versair mini-pump with foot pads|
You can also add a bracket to your frame to keep the pump secure. I used to ride with a mini in my jersey pocket until I crashed and landed on it, bruising a rib! The bracket is a good idea!
|Topeak Road Morph frame pump|
Our internet guy, bike polo star, and bike tourist Matt swears by the Topeak Road Morph for his riding.
3. Frame Pump
The final option is a full-out long frame pump. These generally fit under your top tube with a spring mechanism in the pump. The advantage is that you can pump out more air than a mini. Sometimes a frame pump can scratch your frame paint.
|Portland Design Works Big Silver Frame Pump|
My ride typically determines the kind of pump I use. I always carry a spare tube or two and a CO2 cartridge in my saddle bag, along with a couple of tire levers to get the tire off. When I'm doing a long ride or all-day event, I'll get out the frame pump and a few extra tubes to make sure I don't need to make an emergency phone call home!
ebay did a nice write-up on pump options as well to give you more information.