You can do this with netcat and dd, already on your system. You can set up a listener on the machine to be imaged and then send the dd command to lsitener from the machine where you want the image to be saved. We use it for forensic acquistion of live machines when they can not be shut down, not 100% foresically correct but sometimes it has to do.
Using dd you can either clone the entire hard, copy hdd to image file which can be mounted using the on a loop and accessable within Linux. You can copy sections of the hard disk you can do a whole lot of other stuff that I am not that converse with. Very hadny little tool as is netcat which is a great networking utility.
You could use dd to copy hard drive or partition as a local image file then maually copy the image across to wherever you want.
Try 'man dd' and 'man nc'
Try google for 'netcat' and 'dd' or 'dd clone operating system'
also check out this link to start with