Thanks for the video; so if I understand correctly you can use a dual sim adapter, but you must have a Symbian phone to activate to work, and then put it in you N900.
Can you change the name of both sim cards thru the Custom Operator Widget?
So then all we need is a script/app that could allow us to change cards on some time interval, ie. every 65min. activate card number two; then 60min. later revert back to card one.

edit: So it won't work unless it is activated by another phone most likely Symbian. Correct?