Lambda

  The Greek letter "λ" for liberation. It was chosen in 1970 by the
GAY ACTIVISTS ALLIANCE to serve as symbol of gay liberation, and
in 1974 was adopted as the international symbol for lesbian and
gay rights by the International Gay Rights Congress meeting in
Edinburgh, Scotland.

  Whilst it never caught on in the same way as the PINK TRIANGLE,
it has had its uses. Many organizations, especially in America,
have used it as a way of signifying lesbian and gay concerns together.
It has also been worn in jewellery form by lesbians and gay men to
draw attention to their sexuality to others that are in the know,
and thereby to facilitate "contacts".


                              ~ <Cassell's Queer Companion>