Originally Posted by CodeRage
Plus if you remove more material on one side than the other that blade will be out of balance and you will have a shakey lawn mower.
While true, this statement always make my eyes cross a bit.
It's not hard to improvise a pivot stand. And that is all the majority of sharpening services use anyway. If teh blade leans to one side you take some off that side until it balances on teh pivot.
Or, you just use a reapers file and take a alternate pass across each edge.