AnalogX DNSDig is similar to the Unix DNS tools DIG and NSLookup, but with a bit more verbose output and obviously web based. With DNSDig, you can easily perform low-level DNS queries to any DNS server to help diagnose DNS problems, incorrect configuration, or just to see exactly what's being sent back and forth.
    Operation is simple, enter the name or IP address of the DNS server you wish to query, followed by the domain name you're interested in getting more info from, and finally what type of lookup you'd like to perform. The default DNS server is just my upstream provider; in most cases you'll want to set this to the address of the server you're working on or having problems with.