Dropbox, a way to keep backup of files and competitors

I've been using dropbox for more than a year to keep an online backup of my work, so that even if all my computers crash simultaneously my data will be safe and sound at the "cloud". The free online data-storage is 2GB and recently this free space can be augmented to 10GB (thank god for the competition), by sending invitations to other people (spam me baby). To get ME more online data-space one can follow this address:
https://www.dropbox.com/referrals/NTE2MTc1NTk
and add for me a few MB of free space.
Nice move, since the major competitors offer so much more than just an online synchronization folder.

So the newest addition is the UbuntuONE. Take notice that currently works only on the ubuntu Operating System, although there is an ongoing work from users to port the service to different linux OSes.
What does this service offers:
First of all You got 2GB of personal free data by subscribing to the service.
Then you got access to the UbuntuONE music store, like the itunes/apple store,
you can sync your bookmarks, and share them with the your contacts
and synchronize any folder outside the ubuntuONE folder.
And if I'm not mistaken the announcements still continue to add more features.

Also there is
SugarSync
that is the same as dropbox, but mostly oriented as a paid service, with cheaper service fees, from dropbox (users can sign up for a 10GB plan ($4.99/month, $49.99/year), and offering so much more if you willing to pay, from dropbox (ex. 20GB, unlimited access of files from more than 2 PCs, keeps history backups of more than 2 files back, mp3 streaming from the cloud to every device and more...) and the big one is the ability to synchronize files outside the synch-folder. More on the Sugarsync here.
But I prefer dropbox, since I need only 2GB, and I got almost all the privileges of the paid plan (one thing I don't get is the ability to access more than one history backup file). If you interested in the paid serveices here is a comparison made from the SugarSync developers, no UbuntuONE there.
Also SugarSync supports most of the popular smartphones, BUT there IS NO Linux Support (a great minus for me)

Then there is the BIG announcement for a collaboration between the two rivals, KDE and GNOME (both are leaders in graphical desktop environments for Linux platforms) for the development of a FLOSS Alternative to Dropbox. One that will be opensource, and offer much more than dropbox (don't ask me what)

So, click on the link for the dropbox, to get me more MB, and see you when I see you.