The myth most often associated with Lupercalia is that of Remus and Romulus, the two founding brothers of Rome. Remus and Romulus were thrown into the river by their uncle who wanted to seize their kingdom. Saved by driftwood, the twins were found and raised by a she-wolf (Lupa).
Lupercalia, which derives from the Latin root "lupus" meaning "wolf" started off in the cave called the Lupercal where Remus and Romulus were theoretically suckled by Lupa. There two sets of men (which was later made into three by Julius Ceasar) called the Luperci Quinctiales and the Luperci Fabiani would gather and sacrifice a goat, and often a dog. The goat is said to represent the fertility aspect of the ritual, especially since goats were sacred to Pan or Faunus, a fertility and lust god. The dog is more obscure, though it is suggested that it was sacrificed because dogs are seen as the enemy of wolves. The blood of the sacrifice would be smeared on the Luperci and strips would be made of the skins to use as small whips. The Luperci would then laugh and feast on the meat before starting their ritual run through Rome by the "sacred way," the Palatine. As the Luperci ran through the city purifying it they would whip married women with the skin thongs they carried. This was supposed to impart fertility on the women, as can be seen represented by the picture below:
Some people like to claim that Valentine's Day was made popular in order to eradicate Lupercalia, or that Valentines Day was made to replace it. Though the former was probably true in some manner or other, Lupercalia and Valentine's day hold very few similarities other than date which argues against the latter. Unlike All Hallow's Eve, Christmas and Easter which quite clearly borrowed Pagan traditions, Valentine's Day does not seem to borrow any traditions from Lupercalia unless you consider the broad connection of love and marriage with fertility and lust. The renewal and purification aspect of Lupercalia is certainly lost however, even if the Catholic Church was trying to convert the ancient Roman ritual into a more "acceptable" pattern.
As Neo-Pagans, Lupercalia proves an interesting ritual. The symbolism is clearly very potent and visceral, as can be proved by it's huge and lengthy popularity. However I'm pretty sure if you ran down the main roads of your city or town naked and bloody whipping women today you would most likely get arrested. Be that as it may, the baby does not have to be thrown out with the bathwater. February 14th can still be celebrated by interested Pagans by following it's major themes of lust, abandon, fertility and purification. Maybe instead of sacrificing a goat you can eat some goat curry at your local West Indian restaurant. Instead of blessing and purifying your city by running naked through it's streets (which would be pretty uncomfortable in most of Canada anyways), maybe you could use a map or a labyrinth as a representative. Lupercalia might also be a good time for those with Wolf as a totem to give praise to their guides or even donate some money for preservation of wolf packs in the wild. Those who worship the ancient Greek and Roman gods can take this opportunity to make an offering and a prayer to Pan, Faunus, Bacchus or Dionysus. And for those of you who are fond of Ancient Rome, Lupercalia can be used as a way to read the myth of Remus and Romulus and toast to one of the worlds greatest civilizations.