IP Address Space Management

This handle tool will scan your network and see what IPs are being used and even retrieve some of the devices on those IPs. You can add in comments on each IP and label them appropriately.  No longer will you be pinging 10 to 20 IPs to try to find an available one for a new server.  No need to keep track of IPs on a spreadsheet.  This is the best way to keep track of IP devices on your network.

http://www.solarwinds.com/products/freetools/ip_address_tracker/