--SNIP--
I'm wondering if the two physical keys hiding under the space bar are electrically separate..
I'm not sure how they are wired, but pressing space in such a way that the buttons are pressed sequentially has never double-typed for me yet. It did throw off my touch-typing at first, though. Maybe X or the kernel source might shed some light on this... -shrug-
Actually with the limitations of Busybox and the workarounds needed to squeeze all the Linux juices from this device, the question you should ask is not, "Is the N900 geeky enough for me?" but, "Am I geeky enough for the N900?"