I want to see a ceasefire in the Israeli/Hezbollah conflict (call me politcally naive, but I'd rather we stopped the fighting than used it as a lever). I was going to use the Our World Our Say form to mail the prime minister (http://www.owos.info/lebanon/) but it wouldn't let me change the 'suggested' message. Not only was it not what I wanted to say, but I don't think astroturf helps at all and I'm mailing them to suggest they put in a step to rephrase or rewrite (or make it a lot clearer if it's already there). In the mean time, http://pm.gov.uk/output/page821.asp is the page on the Number 10 site where you can talk to Tony in your own words.
UPDATE: OWOS have changed the wording to explain that they actually send you to the DirectGov site to send the mail, where you can paste in the wording they suggest or write your own.