I don't think they're lip syncing but even if they are, this is probably my favorite tatu live.
Shiina Ringo singing "Aozora" live. I love this version in paticular. Shiina is known for doing different versions of her song and I'm just in love with the Etsuraku hen ones.
http://www.youtube.com/watch?v=04uvmmfJ0yg
This one is really intresting.
http://www.youtube.com/watch?v=0wjZ-J3A-uA
I love how beefy Shiina's voice is. She sings jazz a go go, ufo, jazz a go go honnou, jazz a go go, ufo again (i believe) and they're all fused together.