Second Life is a virtual world that is free to use and which contains al sorts of life-like and completely invented islands to visit. To begin, you need to create an avatar, and it is your avatar that navigates this virtual world. You can use the rich variety of settings available to you in Second Life to create all sorts of animated movies (with your avatar--and friends' avatars--starring as the lead actors!).

Here are some resources that help explain how to go about making your own Second Life movie (or "machinima"):

Before making your own Second Life machinima, it's a good idea to spend some time watching some: