Boards
Silly Signs
Here's a few of my favourites
http://ttpb.co.uk/Imagepages/tube%20warning.htm
http://ttpb.co.uk/Imagepages/SuckedOff.htm
http://ttpb.co.uk/Imagepages/Secretbunker.htm
http://ttpb.co.uk/Imagepages/Fuel.htm
http://ttpb.co.uk/Imagepages/Twatt.htm
http://ttpb.co.uk/Imagepages/Uh%202.htm
http://ttpb.co.uk/Imagepages/Work%20flow.htm
Have you got anymore?