Network Connectivity help please

I'm writing a script to help us manage one of our Class C networks. The page loads all of the host IPs, who owns them, phys desc. of the box, and does a forward reverse lookup on all of the addresses. I'd like to add a column that shows which machines are currently reachable on the network. A simple ping would probably be easiest, but parsing a standard ping for 254 hosts would cause the script to have about a 10 minute load time. are there any quick easy, and most importly, low system overhead, solutions to this problem? Brian Artiaco as0k@excite.com