Hi,
I wrote an app that's called phonelink and is available on the garage : http://garage.maemo.org
you'll need to install the libgnokii package and create a gnokiirc file in your home directory.
It's not as complicating as it sounds !
I've never tested it on a N800 though and I suppose that like Maemo Mapper you might need to install the libbluetooth1 package to have libgnokii working
Don't hesitate to contact me if you have any problem.

Fred

PS : phonelink uses the GPE contact database so it needs sqlite2 (you'd better install gpe contact)