My own solution to getting stuck in one story is to start another story.
This is why I always have so many frying pans in the fire at once :)

(My current projects include but are not limited to:  Furinkan Summer, DNU
6 and 8, BSSM, A Tale of Two 30th Centuries (LSH/SM cross), Summer People
6 and 7, Sailor Moon Z 13, Ta'averen 1/2, Netscape Pi (an unfinished
Otakufic), A Wedding and Four Funerals (Which may need a new title as I
think someone used the same gag), Dance of Shiva--Draft 2, Eternal Game 3,
Parallel Lives 3, Faith, and probably other stuff too.)

Just keep plugging away. Write, write, write.  I've been writing since I
was 12.  The first three years, I produced nothing but pure garbage that I
now hide so no one else will see it.  The next three years produced more
stuff that I hide, but not from everyone.  The three years after that, I
started to write some stuff that wasn't too bad.  Not great, but I don't
hide it.  The three years after that, I wrote one of my favorite stories,
and a bunch of other stuff.  At that point, I was 24, and wrote my first
Ranma fanfic--Putting Your Heart in the Right Place.  This was the first
story I ever wrote seen by more than ten people.  I've written far more in
the last three years, and improved far more in that time than in the 12
before it.  Just keep going.  

Reading a lot helps too.  It's hard to get more out of your head than you
put into it.  

 John Walter Biles :  MA-History, Ph.D Wannabe at U. Kansas         
ranma@falcon.cc.ukans.edu       
rhea@tass.org              http://www.tass.org/~rhea/falcon.html
rhea@maison-otaku.net      http://www.maison-otaku.net/~rhea/

New CS Lewis Quote :)
"This does not mean that we are to be perpetually solemn.  We must play.
but our merriment must be of that kind (and it is, in fact, the merriest
kind) which exists between people who have, from the outset, taken each
other seriously--no flippancy, no superiority, no presumption.  And out
charity must be a real and costly love, with deep feeling for the sins in
spite of which we love the sinner--no mere tolerance or indulgence which
parodies love as flippancy parodies merriment."
--The Weight of Glory