That be 1440x900.
I have no clue to be honest
I would assume that just having so many apps open, along with not ever rebooting the machine (I seem to be able to go a week in OS 9 before I end up rebooting) got me there. I don't really mind though. With 704 megs overall, who cares? 
But yeah, if anyone here has any ideas and wishes to clue me in, please do!