i now think that it won't work.. you know, when you take your battery out and put it in again, ***** "set your time and date" applet starts immediately when you boot your phone... i remember reading few days ago here about a nemo-based kernel (which can be flashed using flasher) which just boots and enables usb mode - try searching, if i find something, i will report here.

edit, found that: http://wiki.meego.com/ARM/N900/Using_Rescue_Initrd no flashing required