Hi, got a solution for android 3.2 tablets (and most likely other versions) . . .
I have an Acer Iconia A100 7" android 3.2 tablet.
Calibre will not see it as it's currently impossible to assign it a drive letter, even with the latest drivers and tools from Acer.
So here goes, I installed "splashtop Remote Desktop HD" (that was a mouthfull . . .)
http://www.androidxmarket.com/applic...-1-9-5-12.html
Now, I can log into my pc (which is downstairs) from the comfort of my long chair in the gazebo, open Calibre, select the books I want, save them to a folder (I use the desktop) and then copy them to my tablet, when I click home, splashtop disconnects from the pc and everything is back to normal.
This is the best solution I can think of and most likely the best one so far that I've seen (there has to be better but I did not see it, if you know please post it!)
I hope you enjoy and please support Calibre, that's an awesome piece of software.
P.S. (sorry about the link, dunno how to show it differently.)