Dropbox - Online Sync and File Sharing
GMX File Storage - The GMX File Storage Manager allows your PC and your GMX File Storage to exchange data via the...
Google Drive - Access and sync your files anywhere
Cloudu - Secure German online storage and file sync service. Apps for all major platforms.
Mega - Secure File Storage and collaboration
Sync.com - Sync. com offers a backup tool and a file sharing service, rolled into one.