Has President Obama ever actually stated that he is for gay marriage?

No. Obama has stated he wouldn't support gay marriage, but his objection is for semantic reasons. He doesn't believe in redefining marriage to include same-sex couples, but he does believe in giving same-sex couple all the same rights as married couples.

I believe he would support what I support -- replacing the legal recognition of marriage with a legal recognition of civil unions -- if not for the likely backlash from the religious community.

Quite the contrary, he used to be against gay marriage! A little into his presidency he said that he may be changing his mind about it and it was an issue he was thinking about, but he's not said he's for federally legalizing gay marriage.

He does not support gay marriage. As a liberal this is one of the things that make me look at the Republican field. Sadly the Republicans outside of Maybe Romney who is starting to go to the right like a asshole is the only Republican I would consider

He has said that he is for equal rights for gay couples but hasn't actually said he's for gay marriage.

He has ordered the Justice Department to stop defending the constitutionality of the "Defense of Marriage" act.

He's explicitly stated he believes marriage is between a man and a woman. The video is on youtube

No but there are several occasions where he stated he was against it until that is he becomes President and needs to pander for every vote he can get.

I believe that's he's actually been against it. But, like an earlier version of Herman Cain, he believes that it's none of the business of the government to intrude.

He has stated that he personally does not believe in it, but that his personal beliefs should not affect it, and that it is a state's issue.

Barack doesnt advocate gay marriage.

Barack Obama really supports it deep down, but he publicly says he doesn't support it as a means to kowtow to right-wing Conservatives.