So I am coming late to this thread, but I would suggest maybe the story you are trying to finish is not worthy? Maybe you need to abandon it completely and start a completely new one?
What I have done in the past if I felt stuck is start editing what I have already. That helps get me back into the story. Another thing to do is... READ. Go read books in the same genre you like, it helps get the mind working again.
BTW way, this was mentioned earlier in this thread and I completely agree go buy and read this book:
http://www.amazon.com/Writing-Stephe.../dp/0743455967