Why not an anti-globalization, mass protest type of mobilization against the war? In other words, get all the people and tactics that you would usually see at a WTO or IMF summit, and have them target the war machine for 1-2 days of protest, and literally try to shut things down like in Seattle and the People's Strike.
Just imagine what it would have meant domestically and internationally if even half or a quarter of those present in DC on the 26th would have sat down around the White House and refused to move.
Instead of targeting international financial institutions, the targets could be the corporate offices of weapons manufacturers and things along that nature. This does, of course, raise some serious problems-- I don't think the authorities would hesitate to use lethal force if a bunch of anarchists approach some government building ready to do something. Also, it would never get the semi-positive coverage that the docile ANSWER protest got. And would the anti-globalization crowd come out for this in the same numbers as they came for Seattle and Genoa? And what would the exact tactics look like? Eh, I guess I'm just rambling. It's an idea, though.