It is hard to say whether I believe homosexuality is based off the natural genetic make-up of a human being or if it is based off the nurture one receives in their environment (whether it be inside the womb or after birth). Still to this day, there are many theories that show correlation, but not causation, of the nature side and nurture side of the homosexuality debate. Can one be pinpointed?
As seen in the video clip of a 60 minutes report (youtube link below), identical twins (twins with the same genes) can still have different sexual preferences. Does this mean it is strictly the environment around someone? Yet, on the other hand, males who have extended family members that are gay have are more likely to be gay. Does this mean it is strongly linked to genetics?
In emphasis of this case (but not in any political bias), during the latest presidential race, Gingrich was asked whether he believes homosexuality is due to nature or nurture. In the best response, Gingrich did not choose one or the other, but simply said he believes it is both. Yet, in the overall view of the topic, Gingrich chose a logical answer in my view. There are multiple, well supported theories on the basis of homosexuality from both the nature and nurture sides.
Although the topic of homosexual creation by nature or nurture is mind-blowing, we should accept everyone for who they are.
Homosexuality: Nature vs. Nurture
"Gingrich on Homosexuality: It's Both Nature and Nurture - CNN Political Ticker - CNN.com Blogs." CNN Political TickerAll Politics, All the Time - CNN.com Blogs. 15 Dec. 2011. Web. 05 Feb. 2012.

I believe that homosexual people can be born with more feminine traits (if male) or more masculine traits (if female) but essentially I believe that homosexual people become homosexual from their environment and choices that they decide to make to label them "homosexual". However, I also believe that in the end all that matters is that all are treated and accepted for who they are.