On the subject of cameras though, the system that Glyn H supplies above is very useful and a lot of companies in the US and more over here are now fitting them to company cars and vans, they are invaluable if the vehicle is in an accident as the evidence is right there to watch.
Under the Data Protection Act, I believe you have to tell every customer by law that they or their property may be recorded/appear on recordings and they have a legal right to request a copy of any footage regarding this. Same applies with any CCTV that captures you - you can legally request a copy. The comedian Mark Thompson (think that's his name) a while back was trying to get everyone who walked down the local high street to request a copy of film from the council because he hated CCTV and wanted it removed for some reason.