>(Also, there's the small matter of how
>to do that without, you know, moving out for a month or whatever.)

I think it may be possible to do it in stages. Granted, this would mean you'd have a breaker panel side-by-side with your old fuse box until the old system is completely phased out... but if you tackle it just one space at a time instead of trying to do it all at once then it may be doable.