Done on Ubuntu, but ought to work similar on other distros. Not sure about Windows, but I would wager a bit yes there too. Now copying an image from ubuntu->windows???, if you pscp probably ya. Same for ubuntu->osx I would wager.
sudo add-apt-repository 'deb http://download.virtualbox.org/virtualbox/debian lucid non-free' i virtualbox-3.2 - Oracle VM VirtualBox so likely "aptitude install virtualbox-3.2" May need to run it once so that it makes local dirs and files THEN cd .VirtualBox scp -rp Remote-Machine-That-Has-Image-You-Want:.VirtualBox/Machines/WinXP . mv WinXP.xml WinXP.xml.save scp -rp Remote-Machine-That-Has-Image-You-Want:.VirtualBox/HardDisks/WinXP.vdi . Run VBox IF BRAND NEW IMAGE, skip 1. 1. Then "remove" your WinXP (or whatever), it will say it cannot open the xml file you moved. 2. Make New, and somewhere you will be prompted for "Use existing hard disk", that is where you point to the WinXP.vdi.... you are done