A recent Gallup Poll finds that the percentage of US residents who accept homosexual relations has, for the first time, surpassed the 50% mark. In terms of religiosity, 42% of Protestants, 62% of Catholics, and 84% of people affiliated with other religions considered homosexuality morally acceptable. The comparable figure for those with no religious affiliation was 85%. Compared with attitudes reported in previous years, the big change was among men, especially those aged 18-49. This group showed a 20% increase in acceptance over the rate reported just 4 years ago.
The poll involved 1029 respondents and has a 4% margin of error. You can view details of the methodology here (pdf).