The sin of the people of Sodom may refer to more than the usual, popular, interpretation. The town's people did not accord the respect and help to travelers normally required of people in their time and culture. Contrast their attitude with the earlier treatment given by Abraham to these same travelers in Gen 18:1-8. Abraham is the patriarch and you might have expected he would send a servant to care for these people but note how he acted:
"When he saw them, he ran from the entrance of the tent to greet them; and bowing to the ground, he said: "Sir, if I may ask you this favor, please do not go on past your servant. 4 Let some water be brought, that you may bathe your feet, and then rest yourselves under the tree. 5 Now that you have come this close to your servant, let me bring you a little food, that you may refresh yourselves; and afterward you may go on your way." "Very well," they replied, "do as you have said." He went on to give them some of his finest food and serve them himself.
In addition, the people of Sodom were attempting rape (Gen. 19:5,9), and the rape of Angels, who were servants of God and members of an alien species. Finally, it seems unlikely that the crowd was composed only of men. In the feeding of the 5000 in the Gospel, only men were counted, but the crowd would have included other people in addition to adult males. Would God have destroyed the town if all the women were innocent? See Gen 18:26-32 in the NRSV where God refers to "righteous" people without gender, or the New American where they are refered to as the "innocent", again without gender. In the New American, it says "all the townspeople" were present, so homosexuality is not all that is going on here. The townspeople seemed so devoid of the love, honor and respect due to others, especially the alien or stranger among them, that their attitudes and actions called out to God for Justice. Read both chapters in Genesis to get a better perspective on the Sodomites sin.
Ezek. 16:49 "This was the guilt of your sister Sodom: she and her daughters had pride, excess of food, and prosperous ease, but did not aid the poor and needy."
Jer. 22:3 "Thus says the LORD: Act with justice and righteousness, and deliver from the hand of the oppressor anyone who has been robbed. And do no wrong or violence to the alien, the orphan, and the widow, or shed innocent blood in this place." NRSV. (Emphasis added.)
Mal. 3:5 "Then I will draw near to you for judgment; I will be swift to bear witness against the sorcerers, against the adulterers, against those who swear falsely, against those who oppress the hired workers in their wages, the widow and the orphan, against those who thrust aside the alien, and do not fear me, says the LORD of hosts. " NRSV. (Emphasis added.)
Isa. 1:10-17 "Hear the word of the LORD, you rulers of Sodom! Listen to the teaching of our God, you people of Gomorrah! What to me is the multitude of your sacrifices? says the LORD; I have had enough of burnt offerings of rams and the fat of fed beasts; I do not delight in the blood of bulls, or of lambs, or of goats. When you come to appear before me, who asked this from your hand? Trample my courts no more; bringing offerings is futile; incense is an abomination to me. New moon and sabbath and calling of convocation -- I cannot endure solemn assemblies with iniquity. Your new moons and your appointed festivals my soul hates; they have become a burden to me, I am weary of bearing them. When you stretch out your hands, I will hide my eyes from you; even though you make many prayers, I will not listen; your hands are full of blood. Wash yourselves; make yourselves clean; remove the evil of your doings from before my eyes; cease to do evil, learn to do good; seek justice, rescue the oppressed, defend the orphan, plead for the widow." NRSV. (Emphasis added.)
For a series of quotes from Jewish religious literature and from the Jewish perspective see What was the sin of Sodom?
The Catechism of the Catholic Church does mention the sin of the Sodomites as one of those that "cries out to heaven" in sec. 1867. These various sins are seen as related in scripture and should therefore give insight into the meaning of the sin of Sodom. The text of section 1867 is:
"1867 The catechetical tradition also recalls that there are "sins that cry to heaven": the blood of Abel, the sin of the Sodomites, the cry of the people oppressed in Egypt, the cry of the foreigner, the widow, and the orphan, injustice to the wage earner."
The footnotes referred to in the text of the section are as follows:
139 Cf. Gen 4:10.
140 Cf. Gen 18:20; 19:13.
141 Cf. Ex 3:7-10.
142 Cf. Ex 20:20-22.
143 Cf. Deut 24:14-15; Jas 5:4.
[For an objective discussion of the translation of the underlying Greek words in 1Cor. 6:9 by a gay evangelical christian see Homosexuality and Christianity which is recommended on the Moral Theology page of the Internet Theological Resources associated with St. John's School of Theology in Collegeville, Minn.]