I use SkyDrive as my main cloud storage, but my teammates mostly using Dropbox. I'd like to know how to sync my files on Dropbox account with my SkyDrive without downloading them first and uploading again. I need both account are always synced on the cloud, so I can access my shared folder on Dropbox via SkyDrive. Please help.
cloudHQ is a service set up to do exactly what you want.
What is cloudHQ?
cloudHQ is a service that continuously synchronizes and replicates data between multiple cloud services and cloud accounts in real-time.
For example, with cloudHQ you can sync Google Drive and Dropbox. So cloudHQ can copy all your files from Google Drive to Dropbox and visa-versa. Also, any change from Google Drive will be instantaneously replicated to Dropbox and any change in Google Drive will be instantaneously replicated to Dropbox.
Or, with cloudHQ you can sync Evernote with Google Drive. This allows you to easily edit Evernote notes in Google Drive or edit Google Drive data in Evernote.
The "Personal Plan" will let you create up to three "sync pair" for $9.99 a month ($99/year). Onedrive and Dropbox are supported, and there is a 15-day trial.
They talk about a "Free" plan on their site (what you're downgraded to if you don't provide credit card details at the end of your free trial) but details on their site are scarce. There are also more expensive plans with more features, of course.