This site has lots of stuff that I've been using for a while now and wanted to share. Some of the more common stuff that I use regularly are the domain whois lookup, the nofollow/dofollow outbound link checker, ip lookups, and the tool that checks header info for 301/302 redirects and redirect locations.
All the tools are here: Free Webmaster Tools - Domain Focus
All the tools are here: Free Webmaster Tools - Domain Focus