Unfortunately for the 810's because of the micro USB connector you still need the adapter cable:
http://www.electronicproductonline.c...oducts_id=2004

Connect Swivel OTG adapter to Mini-Micro cable and you're good to go. Not as slick as on the N800, but it does work (in time I will try to get an N810 version, but right now the costs/volumes required just couldn't be justified because the Micro connector is still quite rare in manufacturing circles).

Thanks,
-Rob