I saw this plant against a fence near Portland, Oregon, and did not recognize its berries. The plant itself looked quite stringy and bare, aside from its fruit.
SOLVED: Stringy-looking plant with red berries
TomH3787 Raleigh, NC(Zone 7b) Sep 30, 2012
It' a nightshade (Solanum sp) - not sure which one (pic of foliage might help).