Cloud storage and desktop/mobile synchronization has become a relatively mature field with multiple players offering great solutions for personal and business use. Here's is my quick list of providers:
- Dropbox - 2GB Free, 100GB $9.99/month, easiest to use
- GoogleDrive - 15GB Free, 100GB $1.99/month, integrated with Google Apps
- OneDrive - 7GB Free, 100GB $50/year, integrated with Microsoft desktop applications
- SugarSync - 5GB Free, 100GB $9.99/month, most flexible
- Cubby - 5GB Free, 100GB $3.99/month, easy interface - paid version includes unlimited direct sync
- Box.net - 10GB Free, 100GB $ 5/month, business oriented
The short descriptions above don't fully capture the richness of each products features which differ substantially.
While each of these provides a system to synchronize your files between a centralized cloud storage system and other devices, there has been a rise in peer-to-peer applications that enable you to transfer files from one device directly to another (without the cloud). This has advantages including speed, security, autonomy and control. In addition to Cubby, I've used AeroFS and BTSync with great success.