Cinemassively: Second Life Lip Sync Viewer
Second Life machinimators know how hard it is to make characters look convincing without their lips moving. There are a number of tricky solutions, but some resident inventors are simplifying the process. mm Alder created a special client that you can use to run SL, and it will loop lip movement.
To demonstrate, he included a scene from an upcoming machinima by Berardo Carboni. If you are interested in this client, please note that there is a normal viewer, and a Windlight viewer, available for download. You can find documentation on the official SL wiki.
[Thanks, Mescaline Tammas!]