In 1997, Artist Rick Buckley originally created 35 noses secretly to buildings in London, including high-profile buildings.
The noses are a cast of his own and created with Plaster of Paris and polymer and usually painted to match the wall placed on. The reason for them is that the artist saw them as a form of silent protest against the increase of CCTV cameras, he wanted to see if he could add them without being caught. Essentially, they are a form of street art.
The most famous nose is located on the Admiralty Arch, and the myth was that it was modeled on Napoleon's and rubbed by horse-riders for good luck.
Well! another myth states that if you find all seven noses, you'll be 'wealthy forever more'.
Today, only about ten of the noses exist. Seven of these are located in (or near) Soho. I am going to keep the locations secret. So that, you'll just have to go for a hunt and explore the secrets of London.
PS On the hunt, you might find the hidden ears in Covent Garden installed by the artist Tim Fishlock as well. There are two on Floral Street but (allegedly) several more dotted around the city.