I just discovered this and wanted to pass it along. I created a subdomain months ago in an effort to conserve on buying a crazy amount of domains. I went to search on d0maintools and it redirected to the main domain and did not give me any info on my subdomain. The sub is seen in search engine results, but I'm unable to get some critical detail I was hoping to find. The d0maintools connects you to a wiki page for the site (freebie back link). Please keep this in mind when using subdomains - if it becomes an important site for you that is making some money, transfer it to it's own complete dot com.