Can Life Live in a Methane Based Environment?

We know that life on Earth does very well with plentiful water and oxygen. We have oceans and a very friendly atmosphere for life here. But what if all the tables were turned and what if we had seas of Methane instead, what would our life look like? It certainly would not have anything similar to mammals running around and the vegetation would certainly look drastically different. This is a rather interesting topic and it became a rather large discussion recently in an online think tank when one member stated;