I got the exact same text on Oct. 25th. When I told them I wouldn't add them to Yahoo Messenger, they went silent. The name changed though to textflirty072. Be careful and don't ever add this person...obviously a scam.
I got a text saying
4996 "hey David u there? have not heard from u in a while."
ME "Who is this??"
4996 "haha if u want to know who this is u gotta add me on Y! msnger. my name is txtiewoman7"