Not sure why the OP's getting such hard time...
But for the record, there's loads of "cultural Hindus" and "cultural Musims" etc. (The Jewish thing is something else entirely - I don't know enough about it to comment.) In India, for example, loads of people are technically Hindu, but do they really believe there is a monkey headed god floating around up there somewhere? Same with Islam - when I lived in Malaysia I had friends who would troop off to the mosque every Friday then come back and drink and party - did they really, truly believe?
I was brought up in a Christian family, and went to church with people who really literally believed in Jesus and so on. Troubles or decisions in their life were accompanied by much prayer and studying of the Bible. I also knew people who went to church and things but didn't really, truly believe it was all literally true (I would think that various politicians claiming to be Christian would fall into this catergory - I mean, IDS or Cameron can't possibly really think they will meet their maker one day - can they? If so, how do they sleep at night?!). I assume when more people were churchgoers in our parent's and grandparent's generations there was more of this kind of "cultural christianity".
I sometimes think that sort of vague Christianity would be rather nice; if we weren't exposed to any other religions, in order to be vaguely reflective/nod to whatever is 'out there'/seek comfort through ritual we could go to church etc... whereas because we know about different religions there seems to be more of a need to really believe or make your mind up about which is true - going to church every week is quite a bold statement to make, nowadays... maybe that's just me though.
Perhaps I am using a completely different definition though...