Keyclone is wicked easy to setup. There are video's and tutorials with images everywhere. What you won't have without it is that your second toon will just be following. He won't attack what your main is attacking, he won't heal you, and you will have to go to your second window and click follow if it breaks. I highly recommend Keyclone, even for just two. You should also look into Jamba, a free addon, that is on this site as well. It will save you a lot of time and headache.