In another topic Rosie O'Donnell said she was going to vote as an "Independent"
That suggests to me that the US population Has to declare which way they are going to vote before any election which in my book is not a fair democratic system!

When did this "Intention" system start?
And of course can you vote in secret(for anyone?) which seems to be very difficult lumbered with this political millstone

In the UK We all vote independently for whoever takes our fancy

Declaring a party is only necessary for primaries in some states. Other states do not require a voter to declare party status to vote in a primary election. The concept has merits. Who better to decide which of potentially several candidates will represent the party in a general election? General elections do no require a declaration. In fact, it may be illegal to require one in a general election.

I'm not sure what the context of the statement was. there is something of a distinction between registering independent and voting independent.

Registering Democratic, Republican, Green, Libertarian, etc. does not mean that you are obligated to vote for that party's candidates, it just means you get a say in who they nominate to run in those elections. Registering independent means you do not get a say in nominations. (As DG said)

Voting independent can mean different things to different people. To some, it means voting for 3rd party candidates (candidates independent from the 2 big parties, or even candidates who are the sole member of their "party"). To some, it means not voting party line (although registering with a party certainly doesn't obligate you to vote for that party, a significant number of people simply vote only for one party). I really don't understand how anyone can't subscribe to the latter, but I know there are people on AP who vote party line.

Me, I'm registered independent and I vote independent in the later sense.

I can give you a couple of examples of how different states work their voting system.

Presently I live in the state of Illinois. When I registered to vote, they did not ask for any political party information. But when it comes to voting in the Primary election, they ask you which ballot you want, Democrat or Republican. So in the Primary you are limited to one political party of candidates to vote on. In the final election a person can vote for whatever political party he wants.

Several years ago when I was a resident of Louisiana, when I registered to vote, I had to register eithr as a Democrat or as a Republican. No other choices. And if I wanted the privelege to vote there, I had to declare one or the other. Also what was interesting in Louisiana, they had an open Primary. The choices in the voting machine, you could vote for any candidate you want. And the final results coming out of a Primary, it was not uncommon for 2 candidates from the same party opposing each other in the final election. Also makes for some pretty interesting elections.