Ce-le-bra-tion times - come on

Cyclo Super Olympic derailleur main image Sugino 75 derailleur main image SRAM X-0 20th anniversary medium cage derailleur main image

What better way to celebrate an historic event (the 1948 London Olympics for example) or a milestone in the history of your company (its 50th anniversary perhaps) than to issue a commemorative derailleur?

Here is a small selection of examples of this arcane practice.