There are a number of reasons why a person should learn Arabic; here are a few:
There are a number of applications that have been created to help you learn Arabic. Simply search for the phrase "Learn Arabic on the iPhone" and you will get a ton of quality results. Since most people keep their iPhone with them at all times, this is a great medium to help you learn the langauge. Next time you are stuck in the waiting room of your doctor's office, pull our your phone and begin studying!
Many colleges have Arabic courses that you can enjoy for a normal college fee. This is a great way to learn because you are kept on a strict schedule and are put in a group setting, so you have peers to work with. Since surrounding yourself with a language is a great way to learn it, network with your classmates and help each other learn faster.
Rosetta stone makes the most popular Arabic software, but there are a number of other companies that have created computer programs that can help you learn the language, too. Check out your local library first to see if they have any free software that you can try before you jump right in to spending hundreds or thousands on computer applications.
Learning a langauge by yourself can be a rough task. Try to find people that are also trying to learn the same langauge and create a study group. If you set timelines and goals, then your progress can be easily measured and it may help the entire group remain motivated and focused.