A friend of mine made a Peach Pale Ale that was delicious. He made some kind of roasted peach puree first, then added that at the end of the boil at flameout. You could add it to the secondary too.
I think it was a couple pounds of fresh peaches, from a U-Pick peach place in Georgia. I suspect there were no better peaches to be found anywhere else in the country that day, and I wouldn't bother trying to re-create it from those bland fuzzy rocks the grocery stores try to pass off as peaches.
Ahhhh fresh peaches in the South .... makes it almost worth putting up with the racism.