Just in case you didn't know, the International Trademark Association (INTA) is right in the middle of its Annual Meeting, which this year is being hosted in Chicago. There are oodles of good programs dealing with various aspects of trademarks, branding, and the issues that arise with them in the online marketing context.  One session focused entirely on online resources that are useful when investigating domain names and domain name holders, whether to clear domains for your own use, or track down the bad guys who are wreaking havoc with you by using domains similar or identical to your trademarks and tradenames.  Here are some of the sites mentioned by the speakers (you will want to bookmark these, or at least a link to this post!):

Alexa.com provides current and historic traffic volume data on internet sites, and allows you to compare the traffic between competing sites, which is useful in a number of contexts.

Archive.org is where you can find the "Way Back Machine", which allows you to look and see how long a site has been around, and track changes that have been made to the site over time.

BetterWhoIs.com is a comprehensive, easy to use clearinghouse for domain name WHOIS information, and is a favorite with the presenters.

Domain Tools was said to provides lots of advanced features for finding information about domains, and domain name holders, some of which is free, and some of which comes with a small fee.  For example, for a fee of about $150 per year, you can evidently access Domain Tools archive of WHOIS information, which provides a chain of title of sorts for domain names.   It also has a reverse IP search available, and typo generator, that assists in identifying domain typos on your domain.

Geektools.com provides a set of technical resources for network engineers and system administrators, which  includes whois and traceroute.

Nation Arbitration Forum provides an easy to search database of their UDRP decisions which makes it very simple to see if there have been any arbitrations involving a particular domain or party.

WIPO also provides a searchable database of its UDRP decisions, but it is not quite as user friendly.

SnapNames was identified as a favorite resource for back ordering domain names.  It is free to back-order a domain, and if it is "caught" by SnapNames, a fee of about $65 is due at that time.  Small price to pay for the benefit of eliminating potential problems with domains of interest.

SamSpade.org  is a freeware integrated network query tool for tracking down spam.

There was also an interesting discussion of the problems posed by the anonymous domain hosting services that are popping up everywhere.  Domains by Proxy was mentioned specifically as one of the more popular services. A good practice pointer - when sending out cease and desist letters to these domains, the letters should go to Domains by Proxy (or the other anonymizing registrant), because THEY ARE THE REGISTRANT and owner of the domain.  That is the way they set up their business model. They will likely respond by saying they are not the real owner of the domain, etc., but the word from the presenters was that if you persist, you can expect Domains by Proxy to respond fairly quickly by posting the actual registration information in the WHOIS record for that domain.