What was the sin of Sodom and Gomorrah?

Lack of hospitality and rape.

Seriously, homosexuality is only hinted at once, when the guards want to rape (key word: rape) the visitors. It's not saying anything bad against homosexuality, only rape. But hey, rape's okay in the bible so long as you marry the person afterwards...

Sodom and Gomorrah were not destroyed due to homosexuality, if that's what you're getting at. God had decided to destroy these cities long before the angels arrived at Lot's house. If all the inhabitants of these cities were gay, why would Lot offer his two daughters to the angry mob? What group of gay men would be interested in women? The threatened gang rape of angels as the ultimate act of disrespect and inhospitality may have been the last straw, but all the gay people I know do not participate in gang rapes. If one bothers to read all the references in Scripture where the sins of Sodom are listed, homosexuality is never mentioned once. Some point to "Jude" and the comments about "strange flesh." "Strange flesh" refers to angels and the sin of humans trying to have sex with angels--it has nothing to do with being gay.

Despite the associate of Sodom with homosexuality, the Bible does not mention a specific offense.

http://lmgtfy.com/?q=What+was+the+sin+of+Sodom+and...

Inhospitality.

Not homosexuality.

Being reluctant to allow a mob to rape one's daughters

A wide variety of things. Rape, debauchery, disrespect, etc.

There is, however, nothing to suggest that homosexuality was the reason.

Lack of hospitality.

They were just party animals, and they wouldn't clean up their act. There was probably a healthy dose of homosexuality too.

Did you ever wander where they got the term "sodomize"?

I think it was petty theft. That's why even until this day petty thieves are referred to as "sodomites".