Ainmating a mouth

I have made a simple character and now i want to animate the lips so that i can place them in any position i want like smiling, laughing, etc. I can’t modify the vertices everytime for it is a tedious process and often deforms the mesh. So is there any way to animate them?

I know you can. There is a video showing face animation in the sintel videos.

Google for ‘Shape keys’.

check out the face rig tutorial by david ward on blender cookie site.
it’s very informative for people new to face rigs and
I highly recommend it.
there are more sophisticated ways of rigging a face but I’d say
that tbe tutorial is a good starting point.