My immediate thought when reading the first post was, "of course there is a gay culture!"
Some of the culture encompasses the strengths of our community, some encompasses the artistic expressions, the myriad of complexities of self identification, the realities of living as "other" in society, and the very real aspects of self protection.
However, it is important not to include in any culture, those actions/behaviors/aspects that are present as a result of oppression, and stigma. That is not a true representation of culture rather a statement of the bigotry and intolerance directed toward a given culture.
So, having said that... define it?
Whew. OK, again initial thoughts. Strength. Strong personalities. Semiotics that go beyond rainbow (albeit a very important one for all that). World views that tend to be more inclusive, not necessarily more understanding-simply more inclusive. Pure love of life for the sake of being (this is one of those aspects that can be a slippery slope to the aspects of culture NOT being inclusive of response to oppression. True love of life is the joy that we feel when we accept who and what we are without any self doubt. Getting there is another story. The very real danger of suicide in teens of the gay community is NOT an aspect of culture, rather an aspect of the oppression of that culture).
Must dash. Have to get to the facility... aren't you happy???