Also -- on previous models that were able to be easily jailbroken, there are third-party aftermarket addons in our Kindle Developers Corner, which enable you to manage collections easily using a calibre plugin. That is what I do with my Kindle Touch.
And they still work if you are willing to do a serial port (hardware) jailbreak.
Otherwise, to manage collections via calibre, you will want to get a Kobo.
