My last 3 batches I have added about 1.3 (packed) cups of organic brown sugar to the secondary. I boiled the sugar in the water I used to top off my secondary after transferring from primary.
I was real pleased with the flavor results of the first 2 (one AAPA, and a dry hopped munich dunkel ale, and I just yesterday did it again with an "angry Irish Red Ale."
I actually got pretty violent fermentation last night, with krausen in the airlock. I will have to transfer to tertiary fermenter in about a week or two.
I wouldn't do it on a pilsener or a cream ale or whatnot, but with the darker, maltier beers I really like the results.
Anyone else do this?