One of the easiest ways to be an advocate for the fight to cure MS or just to have better meds, etc is to go to
www.nmss.org and sign up there for advocacy and you will get emails that tell about different bills, etc coming up and all you need to do is put your zipcode in and the pre-written letters will be emailed to your senators and congressmen.
OOPS, I see the site Cheryl referred to had the correct address
www.nationalMSsociety.org/advocacy