Here in Virginia, Common Law Marriage is not recognized. I believe in most states, you have to have lived with the person for 7 years for it to be considered a Common Law Marriage, but it could have changed since I was in high school (that was almost 9 years ago!).
I am a newlywed and got married July 26, 2008. My husband and I dated 6 years before we were married and while it has been difficult at times, we've made that committment to each other and said that divorce was not an option. My parents got divorced when I was 5 and it was really tough on me.
I am certainly not against people who choose Common Law, but marriage is something I've always wanted and grew up believing it was the right thing to do. Now as an adult, I'm a very liberal person so I don't feel that that its right for everyone, but my rationale is, if you want to spend the rest of your life with some one, why not take it a step further? Marriage just makes the relationship that much more special in my eyes, which is why I did it. My husband always said he'd never get married, and he ended up being the first of his siblings to do so. Of course religion has a something to do with it also, so I wanted to be married and with some one in the eyes of God. I was married in a church, and I had a religious ceremony even though I don't consider myself highly religious.
Its totally a personal decision, but I feel its the right thing to do, especially if you have children or what children. HOWEVER, I DO NOT feel that just because you have children with some one you should get married. I know too many people who had kids together and would NOT be good together married. They ended up breaking up which was best for everyone involved. But I feel that a marriage is better and a more stable environment for children, since I was raised in a divorced family. (Split custody) I do feel it made me cherish marriage more because of that, as well as how to communicate and not to communicate with your spouse. It definitely made me stronger!