Today is Memorial Day — time to remember the fallen who sacrificed so much for our country. Dennis McKeon asked artist Scott Lobaido to replace graffiti art in Queens with flag murals, now they don’t get tagged out of respect — brilliant, resourceful and what a tribute: Here are a few more flag murals to enjoy before you start grilling or doing something All-American to remember the price paid to maintain our Freedom & Liberty. A couple of years ago we went to see Rolling Thunder — all the Vietnam Vets and others on their motorcycles parade over Memorial Bridge. That was quite something to see — a cultural and…