Hide a zip file in an image

Here's how to combine your .gif and .zip.

  cat somefile.zip >> somefile.gif

It turns out that this works with .jpg files as well. Just

      cat somefile.zip >>somefile.jpg

to retrieve the original somefile:

      unzip somefile.jpg

I will leave it to the rest of you to find out what
other image formats work this way.

Remote X session from Linux to Linux

To have a remote X session from Linux machine A to Linux machine B connect to A using the command:
ssh -X 192.168.0.6 -l mylogname

Replace 192.168.0.6 for your IP or hostname.