Well I finally got around to seeing if I could fire the SB-800 remotely in
manual mode using the D70 and the good news is YES!

If you're like me and you don't find the manual very helpful, the SB-800
has a built-in SU-4 type slave which you activate from the custom
functions menu. This can be set as TTL or manual. You also set it to be
either a master or slave and then set the power output level.

To fire it remotely using the D70, all you need to do is put your pop-up
flash into manual mode and crank the power level down to 1/16 (if you
don't want the on-camera flash to affect the subject as much).

Works like a dream! Instant studio! No need for ultra expensive and
sizeable strobes or cables. I think I might just buy a few more of these
in the future.

If you already knew this, my apologies. If you didn't, hey, now you know!