IPsearch - description from Softdepia.com:
IPsearch lets you search the Internet's IP address space - give it a starting IP address and it sequentially searches for HTTP ports and reports summary HTML content. IPSearch can also do a complete Whois function and can convert domain names to IP addresses. Results can be saved and printed. IPSearch comes with a complete Help file and is for Win95/98 and WinNT/2K.
IPsearch is a "Free to try" program. You can download and try it for an evaluation period.