Net::SCP is a pure-Ruby implementation of the SCP protocol. This operates over
SSH (and requires the Net::SSH library), and allows files and directory trees 
to copied to and from a remote server.

* Transfer files or entire directory trees to or from a remote host via SCP
* Can preserve file attributes across transfers
* Can download files in-memory, or direct-to-disk
* Support for SCP URI's, and OpenURI

WWW: http://net-ssh.rubyforge.org/scp