Scott is way more into than I am, but I am coming along just fine. :)
We started being cow-free a few months ago by making the switch to soy milk and banning all cow products from our grocery list. With the start of the new year Scott finished off the salmon fillets we had in the freezer and hasn't eaten meat since (although the Scott family has us over for delicious homemade chili - beef included) I am slowly eating the remaining chicken in our freezer which is tough without Scott.
We are by no means 100% vegetarian (and I could definitely not handle vegan - although I just heard Scott telling his sister that he's going vegan. Something we should discuss I think). If you invite us over for dinner, we'll eat what you offer. We also have our nights where we eat a pizza or have some ice cream, although our stomachs have a tough time with dairy and meat now. It's interesting that the change can affect you so quickly!
So why did we decide to do this? The main reason is health. One example: people are not meant to drink the milk of another mammal. It's kind of weird when you really think about it. I used to be all against vegetarianism thinking "what about your vitamins and protein and stuff?" Fresh vegetables can meet a lot of your daily requirements. We are also mainly gluten free as well and I have got to tell you that physically we both feel a lot better. It's great!
Another reason is not only how animals are treated but how the people running the "farms" are treated. We watched a really great film called Food, Inc (you can find it on Netflix). We highly recommend it.