Omixon release a fast and free cloud data transfer utility, called Cloud Gate.

One of the main barriers with using the cloud is the uploading and downloading of very large files to and from the Amazon cloud environment. Omixon have developed the Cloud Gate utility to do fast parallel uploads and downloads of files of up to 5 terabytes to and from the Amazon S3 cloud storage.

It also works for data transfers within the Amazon cloud itself and includes support for HDFS (hadoop distributed file system). It can be used as a simple command line utility, or can be plugged in to your own applications.