An App to turn off Laptop display when External Display connected?

[Quu]

I've been looking high and low for an application that can automatically turn off my MacBook Pro's display when I plug into an external monitor. I've searched google, I've tried MacUpdate.com I've tried the Mac App Store.

I just can't find an App that does this. To do it I've been closing the lid on my Mac (which puts it to sleep) and then plugging in the Display Port connector and a USB device to wake it up while the lid is closed. This accomplishes my goal of having the Laptop display off and only the external on. But this isn't what I want for 2 reasons:

1. I have to put the computer in to sleep mode which disconnects any active TCP/IP connections I have for VNC, RDP, IRC, IM etc
2. Sometimes when on the 9600GT and you are using the Display Port and come out of sleep the Mac just Locks up and I have to hard reset the machine.

So if anyone can help me find the app I want I'd be most grateful. It doesn't matter if it's free or paid I'm happy to pay for the software.

 

[Hellhammer]

SwitchResX can do that but not automatically I think. You would have to manually disable the internal monitor.

 

[Quu]

Thank you for the suggestion I was really hoping to get something automatic though. And I can't try that software to see if it does what I want without buying it first as they don't have a Trial or Demo.

 

[Hellhammer]

Thank you for the suggestion I was really hoping to get something automatic though. And I can't try that software to see if it does what I want without buying it first as they don't have a Trial or Demo.

It has 10-day trial

You can try SwitchResX for 10 days for free. If it does what you expect from it, if it solves your problem, you are expected to register the program.
You are not downloading a demo, but the full program. This is shareware, which basically means "try before you buy", not "try, solve problem, and trash".

 

[Quu]

I didn't see that, thanks I'll try it out!