Just thought I'd share a lib I've put together and the blog post I wrote about it
http://haskell.zcourts.com/ffi/2014/01/19/haskell-foerign-function-interface-murmurhash3/

The package is available on Hackage http://hackage.haskell.org/package/Dish

And API docs for MurmurHash3 at http://hackage.haskell.org/package/Dish-0.0.0.4/docs/Data-Dish-Murmur3.html

It is a wrapper around MurmurHash3 at the moment but I've got some more hash related utilities I'll be adding.

I'm still pretty new to Haskell so would appreciate any feedback or pointers on any gotchas I may have overlooked.