When you run a building you have to make sure that everyone coming in and out is who they say they are. If you have a system in place that lets you scan IDs as  they come in you have just increased your security cumulatively. If you are looking for some devices like that then you should check out this current online auction for 2 Scanshell 800N Card Scanners. These scanners could easily be hooked into your companies mainframe system and scan incoming IDs as they appear by security. You could probably even hook these devices up to doors for limited access to your more top secret locations. This auction will end soon so find out more here.