[CentOS] using a Laptop as a KVM console?

Hi all,

Has anyone seen something like this before:

I want to use a laptop as a KVM console. Basically when a technician goes to one of our datacentres, or clients he has to look for a free LCD, keyboard & mouse to connect to a server (no network access, reinstall, troubleshoot failed kernel / HDD, etc). And then hopefully there's an open power socker in that cabinet.

So I'm thinking why not just use a laptop instead? It already has an LCD, keyboard, mouse & power. Surely someone has, or may still, build something that could connect to the laptop's USB port(s) and then to the server's VGA & USB / PS2 ports, then act as a KVM?