As seen on the HBO Bill Maher Website (I added the bold):
Now you can listen to Bill and his roundtable guests whenever and wherever you want — with exclusive audio podcasts of Real Time with Bill Maher, available through iTunes®.
We are very sorry. At this time full episodes are only available for podcasts within the U.S.
I here ya. I get so aggravated when I can’t download my favorite shows because I am not in the U.S.
Not so! You can totally see all the US shows you want – just ask me how! Ssshhh, it’s a secret. And if it isn’t on one of the sites I linked to above, then tell me and I can tell you a way to get access to it.