For hosting common files it's ok. Also it is on Android too do, great to transfer files between your Windows and your phone. But if you want better security you have to subscribe a monthly offer.
Ziteboard - Ziteboard is an zoomable online whiteboard that lets team to collaborate in real-time.
Dropbox - Online Sync and File Sharing
Voynetch - Share your visual notes and graphic recordings.
Google Drive - Access and sync your files anywhere
AuthorBee - Organize Twitter around your interests
Mega - Secure File Storage and collaboration