they dont actually show anyone having sex on Friends though...its just sort of implied.
Its not Sex and the City, another tv show which was obviously all about it. In that show it was about four female single friends in NYC, and they have lunch together (not at the same coffee shop) but fancier places, and talk about who they are dating. They dont all live together and for some strange reason, all their family is absent. They all have decent jobs though and can afford to live on their own.
One of the girls, who plays Charlotte, I think it was, also played one of Joeys dates on Friends. She dumps him tho.
That show (Sex and the City) was supposedly about how the four of them were really good friends too, but I dont think they were really THAT great friends. It was more about Carrie Bradshaw having enough copy for her newspaper column about being single in NYC. Carrie Bradshaw being a thinly disguised Candace Bushnell.