I thought you were an MSDN subscriber - imho, Visio is simple to use, and has a great template for creating what you need.

>I'm looking for a small graphical tool to build a network layout. I just need something simple. I'm looking for a free utility which would contains some basic graphics such as servers, hub, etc., and which will allow me to work with objects so I can remove some objects later on and replace them on the graphic.