I really don't think you connected iphone via usb with winscp and Openssh alone, when I used to do this it was a little more complicated tha that.

Either way this tutorial requires indeed wi-fi.

But why would you bother that much since N900 connects "just like that" via usb, plug n' play?
If you think it's worth bothering here's some guys who did it: http://talk.maemo.org/showthread.php?t=37720
Or read this: http://sumoudou.org/相撲外：Mount%20the%...%20a%20PC.html