How do I scp files between SSH public key targets?

[Kenneth Burgener]

Hi,

I have setup my network with public keys, which works great, but how do 
I copy files between two target systems?  My desktop has my private key, 
and I have several target systems with a copy of my public key.  I can 
ssh into any of the targets without issue, but if I try to scp files 
between two targets, it fails as the targets do not have my private 
key.  Is there a mechanism to forward the established authentication 
though a connection?  Is this what ssh-agent is for?  Any suggestions?

Thanks,
Kenneth