Rizos! I was unable to reply to your email! My group had no problems in Spain with anti-war /anti-American centimate. In fact, the Spaniards we met and talked with expressed more curiosity about our feelings towards the war and our president than hostility. However, we are young 20-somethings, so I'm not sure how much that effected our responses.
Our hotel in Madrid (Hostal Adriano) is near Puerta del Sol where one of the largest protests were held, and it was a bit nerve wracking at first, but we experienced no ill-will.
Still, I wouldn't go around sporting an American Flag or pro-Bush t-shirt!
Have a great time.
KV

Thank you for your response! I've cancelled my trip to Madrid; not b/c of the demonstration but more practical reasons. I'll stay instead in Andalucia and spend the weekend driving around the area. I'll do Madrid another time...

Rizos-
So sorry you will miss out on Madrid, but I envy the time you will have down south!
If you are spending any length of time in Seville, I would recommend renting an apartment from Sevilla5.com. We stayed in one of the apartments (Arfe) listed under 'personal style' and loved it!!
It is located in El Arenal, just a short walk from the Cathedral & Plaza Neuva.
Hope this helps!