Ok bill car park tickets is a good idea and I'm sure you can get them for about 30p in some places (or was that back in 2002)
I was thinking about it this morning, when I went into natwest - leaflets, of course. they're everywhere - the library, the banks, the train station, etc etc.
that would do for bonus points, but for the main points i was thinking of something like "go to [insert clue to name of street here] - what colour is the sign on number 12 / what's the name on the buzzer of number 172" etc.
I did a scavenger hunt a few months ago that took place during working hours. There was a few things that were n the list that were location specific, ie getting water from the thames or a pamphlet from a certain movie theatre, but for the most part I just left it upto the rider to furnish positive proof. This could be a reciept, a account balance thingy from a cash point, a rubbing from a sign on a piece of paper, you know.
I'm throwing another one in january, but this time since some people know the drill i'll have to make the proof be takeaway menus from specific restraunts and what not.