Dropbox is one of the best source to store your personal data online and access it from anywhere. You can put your data files on one computer but can access the data available in all computers wherever the internet access is available if the Dropbox software is installed. All the files that you save in your Dropbox online account are stored on the secure server of Dropbox but it requires an account on dropbox to get started.
1. Google Drive
Google Drive gives you the access to upload your personal data i.e, Photos, Videos, Songs, Albums, etc in your one Google account from where you can access your data from all around the world. Get started with Free 5 Giga Bytes and keep all your stuff in one place and then access it from any device, anywhere. You can directly download the Google Drive for following devices:
2. Ubuntu One
Ubuntu One is also a free software gives you the ability to store your data securely, safely, even in one place. You can access you data from all around the world if the Ubuntu One is installed. Currently Ubuntu One supports these platforms -> Windows, Mac, Android, iOS, Ubuntu. You can store upto 5 GB data in Ubuntu one, and on publishing the word with your friends and telling them about Ubuntu One will give you more data storage.
SpiderOak is 100% private online backup, sync & sharing instantly retrieve files from any device, anywhere.
Officially brought to you by Microsoft company which gives you free protected online storage to your personal data. SkyDrive is much like Google Drive.
Box.com provides you a simple secure sharing to your essential documents. Box.com lets you store your content online for free, and gives you the access to manage and share that content from anywhere.