Transferring files between computers.

I have two (of my own) computers but there are actually a total of six on our router, so a system to transfer stuff between computers should be very useful.
One way, of course, is to email the file to yourself. This has the advantage that it can go anywhere in the world and will stay available to download anywhere, anytime for as long as you want.
However, there is a 20 MB limit on Gmail attachments which might be a problem if you want to send over a .tar.gz of a music album, for example.
I've experimented a lot with Giver here (see Labels) and it really works well, but apparently only in Gnome. Certainly I've had problem in KDE.
Another tool I use a lot is cl1p.net which is very useful and can transfer up to 30 MB.
Of course, SSH provides a lot of opportunities for this sort of transfer. This guide is very useful and outlines how to use the scp command.
Essentially, if you have a file Z on the Desktop of your local computer and want to transfer Z to a remote computer on your network with IP 192.168.1.xxx first make sure sshd is running on both computers and then just cd into ~/Desktop on your local machine and type this in a terminal:

scp Z 192.168.1.xxx:/home/user/Desktop

Z will now transfer over without any size restrictions.
As can be seen, scp is essentially the cp (copy) command for transfer between computers.
The guide in the last link also talks a lot about rsync. Here's another, but extremely old, tutorial on rsync. This rsync guide is much more modern.