Pickling

Am I right in thinking that there aren't currently any standard libraries for converting values to bitstreams and back, to be saved in files or squirted over network sockets or whatever to be resurrected later or elsewhere? I'd guess it would be hard to write, too - I've not noticed any introspection. How do people normally efficiently pass complex Haskell data structures to other co-operating Haskell processes? (I am thinking of something a bit like Java's serialisation.) -- Mark