With rising fuel costs and increased commute times from traffic jams alternate, means of transportation are gaining in popularity.  Carpools as well as public buses and rail systems are becoming a more popular option for commuters to get to work.  It's interesting that one of the oldest and most efficient forms of transportation continually gets overlooked.  Perhaps being passed in traffic by a bicycles for many years has given you an immediate distaste for the option, but it's likely that the only thing really stopping you from becoming a bicycle commuter is a poor excuse.
 
There is no arguing that bicycle commuting is a lifestyle change.  Like anything else it will have its advantages and disadvantages, and you will need to make the call about what is right for you.
 
Once you decide to become a part of the cycling community you will realize that bicycle commuters range from college students to some of societies most affluent members.  Hopefully we'll be able to get you over any mental humps preventing you from starting your journey to a healthier lifestyle both physically and financially.  Granted, bicycle commuting isn't a good fit for everyone, but we'll work this out for you in a simplified manner.  Take a quick look at the table below and you will get an idea of how efficient a bicycle is as a means of transportation.

You're probably surprised to find that when traveling only 3 times faster than the average walking speed of 3 mph you could easily travel 5 miles leaving yourself with only a 30 minute commute.  Your 10 mile 1 hour a daily commute could easily make up for a daily trip to the gym for a workout.  The best place to start with respect to bicycle commuting is to see if your "reasons" for not taking the bike to work are actually excuses in disguise.
 
The dress code at my work is not conducive to cycling.
 
Look no further than Holland to debunk this myth.  You will see more bikes in Holland commuting than most anywhere else on the planet.  You will see professionals cycling comfortably in suits, skirts, and uniforms.  With the proper equipment attached to your bicycle you can carry anything you need for work - laptops, briefcases, or even take a shirt or full change of clothes for when you arrive at the office.
 
I live to far from work so cycling is not an option.
 
When using the chart above, it's clear that you can commute 7 miles to work in under 45 minutes.  In many cases, bicycles can take advantage of shorter more direct routes by using purpose built bike paths that do not allow motor vehicles.  Even if your commute to work is too far you can still gain the benefits of bicycle commuting.  For instance, you could ride your bike to the train station or carpool meeting point and save money on parking fees.
 
It is more convenient for me to do the grocery shopping on the way home from work.
 
Bicycles can be fitted with special cases called pannier bags.  Touring cyclists use panniers to carry tents and sleeping bags, and fitting a few groceries from the supermarket is no problem.
 
I don't own a bicycle.
 
You can purchase a used bicycle worthy of commuting on for less than $100.  You local bike shop is a great place to find out what you'll need to get off to a good start.
 
My work does not have showers.
 
Showers are not necessary unless you have a long commute, or you are riding quickly.  In most cases a quick wash in the bathroom sink will suffice.  If you have a commute that is over a couple of miles, you will find that modern cycling clothing does an excellent job of keeping your skin dry by wicking away moisture from your body.  Wiping off with a clean damp towel will have you fresh and clean.
 
I don't have a place to put my bike.
 
If asked, most employers will provide a place to store your bicycle during the day.  Even if you don't have a supportive employer, you can use an inexpensive second-hand bicycle and find a secure place to lock it up.