It's important to note that the aspirin-a-day routine certainly isn't for everyone. Primarily, you should only use this technique if you are at an above average risk of having a heart attack, such as family history or being overweight, and of course, after consulting your doctor.

Some perfectly healthy individuals also opt to go this route, but as this article points out, that may not be the best idea:

http://seniorhealth.about.com/cs/heartdisease/a/aspirin_heart_2.htm