Usually used by people who typically use typed emoticons. Means embarrassment and/or an "oopsie" kind of thing. Similar to ^.^, only ^.^" has a bead of sweat.
You: Did you go and get a date yet?? :D
Me: Mayyybe.... o.o
You: Well where is she?
Me: In my room.
You: Hey where's MY girlfriend!?!
Me: Uhhh.....nowhere! ^.^"