Definition of terms
I remember looking up homosexuality in the New Testament at one point. Depending on the translation, you might not even see explicit mention of it. The KJV uses the term, "effeminate", whereas more modern translations refer to the "sexually immoral" (or something similar). I would be interested to see an analysis of the original Greek in the NT passages to see the actual meaning/connotation of the words in question. Depending on the results of such an analysis, you could make a case for a NT biblical view that homosexual intercourse had been "made clean" (a la split-hoofed meat animals), so long as the homosexual couples lived within the same moral guidelines (eg. refraining from fornication, orgies, etc) as heterosexual couples.
Homosexuality in the New Testament appears to address this. Personally, I draw the conclusion that it is unlikely that the NT condones homosexual activity. It is, however, possible to honestly and sincerely hold this view of scripture, in which case, from a Christian point of view, it is between the individual believer and God, and "who are you to judge another man's servant?"
Are there any arguments in support of the claim that the story of Jonathan and David is not about homosexuality? Because if that's what it's about, I'd think it was really hard to use the Bible as an argument against homosexuality (...even granting the premise of the Bible as an authority).