I had to debug a machine that was behind a DSL-2000 connection, and had about 20 KB/s of upstream. For that, I needed to see what was going on on the X screen, but due to the low bandwidth (and a screen resolution of 1920×1080), VNC was about as fast as 2 frames per minute.

But I found a comparable replacement: The ImageMagick suite has a program called import that allows you to dump the contents of the X screen to a image file. So I took a few screen shots from the console via DISPLAY=:0 import -window root foo.png and then copied the files to my machine.