Hacker Emblem
The Hacker Emblem has been proposed by Eric S. Raymond, perceiving a need for a uniting and recognizable symbol for hacker culture. The image represents a glider formation in Conway's Game of Life. More information on the Hacker Emblem proposal, including SVG and TeX source can be found at the external link below.
Raymond points out that one does not claim to be a hacker by displaying this emblem, but suggests that "by using this emblem, you express sympathy with hackers' goals, hackers' values, and the hacker way of living".