http://www.whoishostingthis.com/ just type in the website address and viola you found the webhost.
uptime.netcraft.com shows you the Operating System, server, IP address, last editing day and netblock owner.
www.domjax.com/ fast domain finder. It shows the domain availability, SEO, validation and research tools.
source:
labnol.blogspot.com/2007/07/how-to-find-name-of-web-hosting-company.html
