Link:
https://www.dropbox.com/
Sync your files online and across computers with @Dropbox. 2GB account is free!
Sync
Dropbox allows you to sync your files online and across your computers automatically."
* 2GB of online storage for free, with up to 100GB available to paying customers.
* Sync files of any size or type.
* Sync Windows, Mac, and Linux computers.
* Automatically syncs when new files or
changes are detected.
File Sharing
Sharing files is simple. It takes only a few clicks.
* Shared folders allow several people to collaborate on the same files.
* See other people's changes instantly.
* Use your "Public" folder to link directly to files.
* Control who has access to your shared folders. Kick people out and remove the shared files from their computers in the process.
* Automatically create shareable online photo galleries out of regular folders.
Online Backup
Dropbox backs up your files online without you having to think about it.
Web Access
A copy of your files is stored on Dropbox's secure servers. This lets you access them from any computer or mobile device.
Security & Privacy
Dropbox uses military grade encryption methods to both transfer and store your data.
Mobile Device Access
A free application for iPhone, iPad, BlackBerry, and Android that lets you access and manage your Dropbox on the go.
Thanks. It's the easiest online storage, sync, backup solution I've found so far and I have tried a lot!!!.
https://www.dropbox.com/
Cloud Computing (free online storage) 2gb + more 
