ps - here's how to access cloud storage ( drop box) with sony readers- I found this with Google - have not done this myself but if it works for sony T1 then it should work also for T2 & t3.
maybe it can be done with kindle PW - dunno - if so then it s another way of having even more books on tap:
Sony PRS-T1 can use Dropbox to transfer files from your gadget (i.e. computer, mobile phone). This is a really convenient way of transferring files without having to the Sony Reader PC software and connecting it with a USB cable. The steps are quite straightforward:
On the PC
Install Dropbox
Create a Dropbox account
Load up files into Dropbox
On the eReader:
Start basic browser
Go to www.Dropbox/m which is the mobile version of the website
Log in
Select files (eBooks) to download
Exit basic browser and go back to main menu, which shows the newly downloaded eBooks
Open eBooks
I may get around to testing it as my calibre library is backed up to dropbox already, but I have no
need for this. I am happy with calibre + a USB cable