There's a new (?) Swedish website dedicated to text messages that were sent to the wrong person http://www.felsms.com/
We've all done it.
My favourite is one that reads:
"Have you seen Linnea's baby? I was almost scared. You could see the veins through the skin on its head. A bit like an alien. And then he looked like his father and that's not exactly good news either."
Let's just say that Linnea was not impressed.