Finally cloud service ,the best popular service.

1.DropBox:
Give you 2GB free
http://dropbox.com

2.iCloud:
Give you 5GB free only for iDevices and Mac.
https://www.icloud.com/

3.Google Drive:
Give you 5GB free
https://drive.google.com/start#home

4.Microsoft SkyDrive:
Give you 7GB free
https://skydrive.live.com

5.Box.com:
Give you 50GB free
https://box.com

5.Copy.com:
Give you 15GB free
https://copy.com