Yeah, not to pile on, but Vicky and Jewlz and the others here are not suggesting to get married because they are all pro-marriage nutters. They, like the rest of us, are pragmatic. They are saying this because the rules are written this way to make it difficult any other way.
We just have to set aside our pre-conceptions about marriage, just like Britney Spears. We had another thread about "playing the system" and in my opinion, this is how you play the system. You show up at a registrars office, fill out some paperwork and in the eyes of the law "get married". If down the road, you want some big to do, you are more then welcome to have it. The government can't touch what is in your heart, but if as long as you are comfortable living together and getting on with your lives, then let go of your pre-conceptions and crack on with it.
[Edit: too add the rather critical "not"]