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.
fruux - Free service that takes care of your contacts, calendars and more so you don't have to.
Dropbox - Online Sync and File Sharing
FullContact - Put the power of full contact information into your web or mobile apps.
Google Drive - Access and sync your files anywhere
Google Contacts - Google Contacts is Google's contact management tool that is available in its free email service Gmail, as a standalone service, and as a part of Google's business-oriented suite of web apps Google Apps.
Mega - Secure File Storage and collaboration