Hi Michelle,
Apparently "black furry tongue" is a pretty common condition, and for most people it's temporary. It's the papillae of the tongue growing longer than they should.
http://en.wikipedia.org/wiki/Black_hairy_tongueNobody seems to have a solution, and for me, following my treatment, I had this for, well, about 1.5 years! But, recently, it seems to have gone as mysteriously as it came. This change, or my noticing of it, seems to have coincided with a dental cleaning, but I wouldn't go so far as to claim that the two are linked. Maybe?
The good news is, it seems to go away, eventually.
-Seth