I know I can install Samba or openssh-server to be able to share files between two Ubuntu computers. Is there a way to share files without installing additional packages?

I installed Ubuntu on two systems on the same LAN, but without Internet connectivity. I found that my usual way of transferring files (scp) failed because openssh-server was not installed on either system. Using Personal File Sharing was impossible without installing extra packages. I ended up using netcat to transfer, which is suboptimal and not intuitive for the average user.

So I'd like to know if anyone knows of a way to do this with out-of-the-box Ubuntu installations (or at least, with packages available in the Ubuntu desktop CD).

Thanks!