From what I've read, when Obama was younger (I think I'm getting this from a former girlfriend as quoted in Vanity Fair a couple months ago), he pronounced his first name Bar'-ack (when he didn't go by Barry).

When I was married to my first husband (1970-1979) I annoyed his family by pronouncing the family name (which I took when we married and divorced when I divorced him) as it would be in Italy. Of course, no one outside the family could spell it and most of them murdered the name no matter how they pronounced it.

Linn