Just in case anyone's thinking it'll just be ten of us in London. Nicked from the Stop The War website :

One of many international demonstrations against the War on Iraq taking place on 12 April:

Adelaide
(13.04), Athens (16.04), Auckland,
Antwerp,
Basel,
Berlin,
Brussels,
Buenos
Aires, Barcelona,
Channo,
Copenhagen,
Cyprus,
Delhi,
Dhaka, Dubrovnik,
Glasgow,
Gothenburg, Gujrat, Haifa,
Halmstad,
Helsinki
(13.04), Hiroshima (7.04), Hong
Kong, Hoshiarpur,
Hyderabad,
Joensuu,
Khartoum, Kolkata,
Ljubljana, London,
Los
Angeles, Macedonia, Madrid,
Malmo, Managua, Manilla,
Maribor, Melbourne,
Mexico
City, Montreal,
Oslo,
Osijek,
Ottawa,
Oulu,
Paris
(+ 50 other French cities), Patna,
Puerto Rico, Poznan,
Quebec,
Pula,
Regina,
Rijeka,
Rome,
Rotterdam,
Salonika,
San
Francisco, San Juan, Santo Domingo, Sao
Paulo, Seattle,
Seoul, Shannon,
Sherbrooke,
Split,
Stockholm,
Sydney (13.04), Tokyo,
Trois
Rivières, Vaasa,
Vancouver,
Victoria
(13.04), Vijayawada,
Visakhapatnam,
Vukovar,
Warsaw,
Washington,
Zadar,
Zagreb
…and lights out all over Spain.
See also PaxHumana.

website@stopwar.org.uk
On this Saturday's demonstration we are asking people
to bring flowers, cards, wreaths or whatever you
think is appropriate, to lay outside 10 Downing
Street as we walk past there. We will also be stopping
both demonstrations as they arrive at Parliament
and holding a 2 minute silence. This will be in
memory of all those who have died so far in Iraq.