In the world of KVM switching, there is an emerging technology called KVM over IP. This allows you to have the basics of a KVM switch, whether it is a USB switch or a DVI KVM switch, and access those servers from anywhere in the world that you have internet access. KVM over IP switches can be especially useful if you are not on site with your servers, as you can connect to them and configure them all from anywhere in the world with one IP address! KVM over IP solutions can range in size from a 4 port KVM over IP switch or up to 1,000's of servers. There are also management appliances for KVM over IP that can be used to have global control over many KVM switches, KVM gateways, and any other devices on your KVM network. With KVM over IP you use a client such as VNC viewer, or a webbased Java client. These give you connection the server in the KVM over IP switch, and allow you to have communication to the USB or PS2 attached servers.
You can use DVI or VGA video with KVM over IP switches. You can also give IP access to an existing non IP KVM switch. This can be especially useful if you wanted to keep a legacy KVM switch in place and still have IP connectivity to your servers. You would need a KVM gateway to attach to the console side of your KVM switch, and that acts as a buffer between your switch and the internet. I see KVM over IP as a rising technology and I think in our fast paced world you will see more and more KVM switches migrating over to KVM over IP.