I have one co-worker in particular who is...well... nosy.

We work in what I fondly call 'officubicals'. I have 4 walls and a door, but the walls only go up 8 feet and do not touch the ceiling. So pretty much I can lock someone out from looking in on me, but they can still overhear conversations (be it phone or otherwise)

This lady always feels like putting her two cents in. Bleah!