With Fictionwise being slowly pushed under by Kindle and Nook, perhaps it's time to add a bookstore with little or no DRM to Ubuntu. The thing that Fictionwise is really good about is making it very clear which books are encrypted and which are not. Furthermore, books encrypted for eReader are encrypted to a user name and password, not a specific copy of Adobe's Digital Editions.
I can still read all but ten or so of the hundreds of books I've bought from Fictionwise over the last decade. I don't trust Adobe to provide a similar experience with it's DRM service.
In Germany you can pay downloads within the Ubuntu One Music Store with credit card and the payment services firstgate, Click&Buy and PayPal. Many of those services do have a bad reputation and/or need also a credit card. Because of this many people without credit cards won't be able to buy music.
In Denmark we have several popular music services, where you are able to stream all the music you want for a monthly fee. That is not possible in Ubuntu one music store (rythmbox).
Thunderbird gets in Version 13 alpha Dropbox support. It means, that you don\\\'t have to send the whole big file anymore, it will be uploaded to your Dropbox and the recipient gets just the download link.
The files you uploaded to your Ubuntu One cloud may contain sensitive information. Someone who has found out your password can access these files. There might be a way to make this way safer.
in this way is possible to use a remote cloud-based storage like a local storage, in this way we can use softwares like TrueCrypt to obtain a remote secure storage.
In this way we are sure that nobody can modify or view our files, because in my opinion cloud based storage have the problem of the loss of control of the data.
Ubuntu currently lacks a proper backup system but yet linux system settings are usually the most modified. However, with Ubuntu one cloud storage built in, critical system files, eg. Xorg.conf, etc can be encrypted and stored online in a compressed format.
Then if your pc crashes, you reinstall OS etc, then you can restore all your settings from the ubuntu one sync.