As I said in another thread, if protesters are really keen on stopping the war - it's not going to get done on US soil. Go where the war is actually being fought and protest there.

If that doesn't appeal to you, then call and/or write your congressperson. Repeatedly. Relentlessly. Give your beliefs and opinions a name to go with them, not just some anonymous crowd sound-bite on the evening news.

Write letters. Make calls. Don't tie up the whole damn city.