Using a laptop as an external monitor and keyboard for a server?
From a hardware perspective, there is no straightforward way to do that. The video ports on most laptops are outputs, not inputs, and you can't reverse that. The keyboard/mouse ports are inputs, not outputs. Most USB controllers inside your server and laptop will fight over devices connected to the same bus, so attaching them via a hub is also not practical.
- Use some remote desktop/vnc/X-terminal (but of course, why do you even need to be in the server room?)
- If your system has a serial port and a boot management processor (like iLO) you can connect directly to the BSP, which will then generally let you get a terminal session on the server. This is true for both *nix-ish and Windows systems. HP Integrity servers tend to have this capability.
There is a KVM from Epiphan Systems that connects your laptop to the monitor/keyboard/mouse of another system using a USB based VGA framebuffer. At $399 the price may be a bit steep though.
http://www.epiphan.com/products/frame-grabbers/kvm2usb/
Use servers with "lights out" modules. This way network is all you need and your notebook will be a nice terminal.