I regularly need to do whois lookups as part of my work, and one of the best tools for doing this quickly is the tiny whois package which is used from bash – I don’t know how many people here ever need to look up whois data, but, this way is considerably better than trawling through various ISP’s websites, and even easier than DNSStuff’s utility.
You can install the application by using:
sudo apt-get install whois
(The package came out of the xnv4.xandros.com etch/main repo, so you’ll need to have this configured in /etc/apt/sources.list, and potentially pinned as well.)
Usage of the tool is dead easy:
whois [domain name]