Firstly .. read thishttp://blogs.abcnews.com/politicalradar/2007/11/obama-says-flag.html
Secondly, I was talking to my roomie (naval officer) about this who said there are different rules when it comes to the National Anthem depending on whether you are in uniform or not. He said that even the different branches of service do things slightly differently. He said in some cases he would salute, and some cases you just stand at attention. The hand over the heart thing was made up by someone (I don't know how binding it is anyway) but not really a matter of respecting either the Flag or showing patriotism.
I know there are some religious sects that will not even repeat the pledge of allegiance for religious reasons (idolatry etc), and they are perfectly in their rights to do so. I would not judge anyone for how they show their patriotism.
If you care about this country enough to try to change things for the better, thats all the patriotism I need to see. If you love the constitution and bill of rights where it comes to individual and collective freedom that is what I care about. When you lie to and deceive the American people and spend their money like there was no tomorrow, run the country into the ground, disrespect due process, and circumvent laws meant to protect us, etc .. then all the pledges, anthems, and reverence mean nothing