Attached is an example hip and otl's for my latest SSS solution. Have a look over at the oDforce forum's very large SSS thread for some bg info.
It's basically an implementation of nvidia's diffusion and color profiles as used on their human head project. I have no idea wether my shader actually tracks their data correctly, but it look alright

The head to the left uses a point cloud variant of the shader (handy if you are rendering full screen views of gory internal organs), the one to the right is per-pixel.
The thing in the middle is there to show how you can handle internal occluding objects, as well as internal glowing things, the front light is excluded from this object to show the effect more clearly. Bear in mind the effect is not correct in that shadows are being cast along the surface normal direction rather than towards the Light (i.e. if you move the back light around the shadow from the houdini twirl will remain static), I may do an update in the future that does this correctly.
The render took 2m16s on a i7 965 (23s if if rendering only the Pcloud'ed head) . If by chance you find it renders like 30 times slower than this on your machine, post your houdini version here, I found some render time oddities that I will have to contact support about.
Things to be aware of:
If you want to use area Lights you will need to set it's samples to 1 or 2 (the shader will add more)… so if your light has 2 samples and the shader is set to 16 the actuall number of shadow samples taken will be 2*16=32… that means you may need duplicate light rigs for dealing with sss shaded stuff and regular stuff at the same time, via light masks. I dont know how or wether it's even possible to override shadow sampling from the shader.
The point clouds used in the render bellow are actually the mesh itself. Although you can use the scatter Sop if you wish, I personally like using a subdivided mesh because it's inherently stable (as long as topology is unchanging) and often creates just the right point density in the right places.
The Shader will not appear in reflections!! I'll try and figure this out sometime.
There will probably be more updates in the future as I use this more and more. At the mo it's as free of artefacts as I know how to make it


The vop otls are subnets, so feel free to poke around and point out my mistakes/inefficiencies

Cheers
Sergio