So lets say I'm executing a command on the CLI and it spawns a GUI and I forget the & at the end. Now I want my shell back, so I hit a ctrl-z but the GUI locks up! Is there any way to do a ctrl-z without locking up the GUI? I am using Linux with a bash shell, xorg and gnome. This is an Ubuntu system.
Use bg to put the command that you have stopped in the background.
Check out GNU Screen. It is very useful for this type of thing as well as offering a bunch of other terminal multiplexing functionality that can be very nice.