All in how you define the word:
Gay:
Lesbian:
If you want to talk about gays AND lesbians, using the term "homosexual" works just fine. If "Gay" can apply to homosexual women, why would the word "Lesbian" even be neccessary? To describe a female subset of homosexuals, perhaps? There's a reason, to me.. for Gay AND LESBIAN support groups. In most social circles, I'd argue -- gay refers only to male homosexuals, and I hope the vagueness of "gay" as referring to all homosexuals does not persist.