Assuming you want to input parameters of a fake network, given IP ranges, a mix of machines and configurations, and have it spit out a fake report of a 'typical' network. I assume you want to do this without actually having a network at hand.
You could create your own simulator by grabbing 'typical' data from posted nmap scans and storing them, categorizing the results of various machine configurations (Windows, Linux, router, etc), and then parameterizing the IPs, machine names, etc. Then write a script that processes the variables you need (20 Win2k3 servers, 10 Red Hat Linux servers, 2 Cisco routers, ip range 192.168.1.0-255) and add in some randomization to the other scan results.
This would create a convincing nmap scan report and you could create as many reports in as many configurations that you need.
What I am NOT sure about is how useful such information would be ...