Are hand sanitizers a good option for preventing the common cold?

Yes. Yes, but.... Hand sanitizer use can prevent the common cold as this is caused by viral infections; however, at least one study has shown that the regular use of the hand sanitizer has resulted in increased bacterial resistance (due to the continued exposure to the sanitizer.).
Yes. Hand washing and personal attention to hygeine certainly play a role in preventing the spread of viruses. Alcohol based hand sanitizers are certainly a good alternative to soap and water and about as effective if used correctly. The big advantage of hand sanitizers is that they are readily availible and quick to use. The impetus is still on the person with the cold to not spread the germs.