You can copy files between machines within the theory group (assuming that both are running linux) using "scp". This is the secure version of ftp. (If you want to know how to copy files between your computer while it is running windows and another computer which is running linux, see for details.)
I'll now give the example of copying a file from your desktop PC to pyserver, the syntax is (assuming you are logged onto your desktop PC):
scp filename pyuser@pyserver:
Note "pyuser" is your username on pyserver. (You will be prompted for your pyserver password.)
If you are logged onto pyserver, then the same thing as above can be achieved as follows:
scp pyuser@pydesktop:filename .
This will copy the file "filename" on pydesktop to the local directory of pyserver.
You can modify the above by adding directory structures, eg.
scp pyuser@pydesktop:tex/latest_paper/figure1.eps .