For those who condemn homosexuality as a sin, I want to show how it isn't one in Buddhism.

"Aware of the suffering caused by sexual misconduct, I vow to cultivate responsibility and learn ways to protect the safety and integrity of individuals, couples, families and society. I am determined not to engage in sexual relations without love and a long-term commitment. To preserve the happiness of myself and others, I am determined to respect my commitments and the commitments of others. I will do everything in my power to protect children from sexual abuse and to prevent couples and families from being broken by sexual misconduct."
Thich Nhat Hanh has a commentary on the 3rd Precept.

http://dharma.ncf.ca/introduction/precepts.html