Subsurf Question

i am in the proccess of making one of my first higher-poly models and have run into a problem.
i subsurfed the main body piece and applied it, and now i realise that was a bad decision. is there any way of “undoing” subsurf? like another modifier i have tried?

An thread about reversing subdivision. http://blenderartists.org/forum/showthread.php?t=151820&highlight=subsurf+reverse
Search the forum for other threads which may be helpful.

Richard