I had an idea for a terminal app, but this being Linux, I figured someone has probably already made it, and I should ask before making an attempt at doing it.
The idea is a terminal with a separate, dedicated input area. Some mainframes had this, but for some reason Linux does not. So if your terminal is being flooded with messages (just try to access a faulty flash memory card), you can't see what you're typing. With a dedicated input area you can still enter a command to try to stop the madness.
Of course, a graphical frontend can't exactly change how the terminal works, but it can have a textbox, where every keystroke you type, including backspace and enter, is sent to the terminal, and enter also clears the box. That would be about the same effect.
Additionally, if it's possible, the app could detect if the command has finished executing yet, and if not, any additional commands you enter would execute as soon as the current one is finished. You can already do that with Ctrl+Z, but this would be a more convenient method that doesn't require you to stop the current process.