This page "Berries of the San Gabriel Mountains"
http://home.earthlink.net/~zelicaon/sgm/blooms/berries.htmlhas pictures for most of the berries you will find on the trails.
I, too, am still looking for reasonably good pictures and will continue to update the page as I find them.
Some great berry locations are:
Chokecherry, across the street from Mt. High
Bitter Cherry, at the entrance to the Lightning Ridge Nature Trail
Alpine Gooseberry, at the beginning of the oak glade on LR Nature Trail
Mountain Gooseberry, towards Lamel Spring on B-P Trail
Serviceberry, on Manzanita Trail
Wax Currant, on the trails around Jackson Flat Group CG
a little bit of everything on the Big Horn Mine Trail
I think the official Wrightwood food should be Wrightwood Wild Berry Jam. It the berriest place I know!