I'm on ubuntu 11.04 running virtualbox and I have windows 7 on the virtualbox.
Sharing a host (linux) folder with windows (guest) is easy. How do I access the windows (guest) filesystem from linux (host)? There doesn't seem to be a way to share windows folders with linux through the virtualbox interface.
If you have the guest set up as a bridged network, you can share a folder with Windows sharing and mount it in Ubuntu as a SAMBA share (using the guest's IP address would probably be easiest.)
There isn't a direct "Virtualbox" feature for sharing the guest resources to the host the way Virtualbox can share the host's directory with the guest as far as I know. Unless you have a reason to do a host -> guest share, it's less intensive to put the files in question on the host and share to the guest since you're usually accessing the disk image when manipulating files on the guest.
But anyway you can treat the machine as if it were just another machine on your network and use traditional Windows sharing to get files from the guest to the host.
