3 pages in <24 hours. The usual. I notice that there are a lot of (nearly all against) religious arguments. To those arguments:
1. Most of you live in secular nations where laws are supposed to be completely separate from religion, and no marriage was created (historically) before monotheism so all Christian arguments cannot be used as Christianity CERTAINLY did not create marriage.
Maybe Christianity isn't against homosexuality, it is at least arguable.
@BlueSano: I have already attacked your point of "marriage was created by religion", but to your disease argument: The only reason why gay people spread STIs/STDs is that they did not know any dangers of unprotected sex, gay marriage will only make knowledge more spread, and also lesbians do not spread diseases.