DUDE!
the head mesh is huge! I loaded it up in maya and it's like 9000 polys! Thats like 2 Model pack 4 characters! The Uv map is a bit odd too. Anyway, it's a nice contribution, but I think you need to work on optimising it. As you can see from the attached screeny, there are literally 1000s of wasted polygons inside the head. For example, the left eye, has 25 visible polys, but it's made out of a 257 poly sphere. So there are 227 polys just sitting inside the mesh, not being used.
I know this sounds like a really harsh crit, but I'm just trying to help y'out. Try isolating each of the meshes and deleting the bits that you can't see from the outside. then use poly reduce on some of the other bits like the neck cap. Wow. ok, the neck cap (the bit that covers over the bottom of the neck is 5000 polys. It could just be one face with maybe 5 subdivisions.
I'm interested as to where you got the head mesh actually. THe head itself was obviously created by a very talented modeller, but the eyes, brain and neck cap seem to have been cobbled on afterwards. I don't want to be a spoil sport, or point the accusing finger, but did you actually make the head? Its just that if you have the skill to model the eye sockets and lips so nicely, why did you go throwing in sphere primitives for the eyes, when you could have just modelled them straight to the sockets?
butters
