Now what the symbol means or meant when it was introduced are a prime topic for speculation and a morass of public rumoring. Some of the more popular rumors are:
*Simply, the Greek letter "L" stands for "liberation."
*The Greek Spartans believed that the lambda represented unity.
*The Romans took it as meaning "the light of knowledge shining into the darkness of ignorance."
*The charged energy of the gay movement. This stems from the lambda's use in chemistry and physics to denote energy in equations.
*The synergy which results when gays and lesbians work together towards a common goal (a gestalt theory which also stems from the physics-energy theory).
*The notion that straights and gays, or gays and lesbians, or any pairing of these three, are on different wavelengths when it comes to sex, sexuality, or even brain patterns. This again comes from the lambda's presence in chemistry and physics, where it is sometimes used to represent the wavelength of certain types of energy.
*An iconic rendering of the scales of justice and the constant force that keeps opposing sides from overcoming each other. The hook at the bottom of the right leg would then signify the action and initiative needed to reach and maintain balance.
*The lambda is also though by some to have appeared on the shields of Spartan and/or Theben warriors. The Thebes version is more popular because, as legend has it, the city- state organized the Theban Band from groups of idealized lovers, which made them extremely fierce and dedicated warriors. Eventually however, the army was completely decimated by Kind Philip II, but was later honored by his son Alexander the Great.
There is no actual evidence though that the lambda was ever associated with this group. However, there was Hollywood movie in the 1962s called "The 300 Spartans" starring Diane Baker, Richard Egan, and Ralph Richardson that showed Spartan warriors who appeared to have lambdas on their shields.
Whatever the lambda meant or means today, it's everywhere. Even though at one time it acquired a strictly male connotation, it is used by both gays and lesbians today. Back in December of 1974, the lambda was officially declared the international symbol for gay and lesbian rights by the International Gay Rights Congress in Edinburgh, Scotland.(information contained in this blog taken directly from www.lambda.org)