I have a sketch that is *welded* to its cel.  
I've tried the freezer trick, and it loosened a 
few edges, but that's about it.  I don't really 
want to to try the water method since I'd rather 
leave the sketch were it is than damage it.  I 
recall reading somewhere that you could, with 
great caution, use a hair dryer to warm things 
up.  Has anyone tried this method?