I think Brighton is the worst for this. You see them with their clipboards, their top which advertises some charity / organisation, and they wont let you pass. Well they do let you pass but its really annoying.
I will never forget when my 7yr old was having a bit of a strop, and i was trying to calm him down, and this woman was trying to talk to me about whatever, oblivious to what i was doing. I spun round on here, and said 'seriously is this a bloody good time to talk to me!!!'.
The best time though, was when i was eating my lunch in town, and this woman just sat down and asked me questions, for a survey she was doing.. i just carried on eating...
Its worse when they come to your door though, and this happened just the other day, this guy from St. Johns Ambulance wanting me to sign up, donate to get more people aware of CPR. I told him i was a nurse, that i had regular CPR updates, and that i had trained my family also, but he still wanted me to sign up. In the end i shouted at him, and said, 'isnt it enough i work 50 hours a week looking after dying people, and that i donate to NSPCC, how much more am i supposed to give? He just walked away...
I guess they have a job to do, but man, some people just annoy the hell out of you..