This spell can be rather useful in many different situations. Part of it's spell description says that it extinguishes the fire source it is cast upon. This can be useful for putting out things like forest fires and the like in case they have to be done in a hurry. Of course, you have to deal with the normal effects of the spell so be careful.

Now, in theory, if you cast this spell on a fire elemental or the like it should extinguish the baddie. I have not yet tried this but I plan to ASAP.