Ah, ok. I was thinking with ssh keys installed to connect to the other machine (laptop in your case?). I run duplicity to a remote machine that changes IP, but is always accessible- using ddclient in my case but could be anything. The server machine runs the script, scp's the files across and closes the connection without the need of password authentication.
*to clarify, in your case you'd need to have an ssh server running on your laptop