Flu + You is a national public education initiative from the National Council on Aging with support from Sanofi Pasteur. For more information on the USA Flu + You campaign. For direct access to the PSA.
In Ontario, Canada, you can get it free from your doctor, or at any number of pharmacies:
Lots of employers have set up flu clinics, as well!
Information about the flu and how to protect yourself and your family.