How can I use my laptop as a 2nd monitor?
I would (and have) do this workflow in running apps on the secondary laptop "monitor".
- Install and configure laptop as a Synergy client.
- Start up Synergy and make sure you can control the laptop from the primary workstation.
- Make sure SSHD is running on the local workstation with X11 forwarding enabled.
- SSH from the 2nd laptop with X11 forwarding.
- Start the (GUI) program(s) you want to run on the 2nd laptop display. They will forward over X11, and you can control them through Syngery.
I did this at a company where I had two laptops, and it worked quite well. It's a bit of work to set up, but worth the effort. Of course you'll probably want to set up your ~/.ssh/config along with this for automatically setting SSH settings. I haven't found any software that was much better, if it even provided this functionality, that worked on Linux.
What you are looking for is an XDMX kind of technology.