Useful websites for Sysadmin, Network administrator, IT Architects, developpers
lot of services like: NSLOOKUP, DIG, WHOIS, TRACEROUTE
Useful when you're behind a Proxy.
Sometime you have "%20 %" when you copy some URL on the internet. You can decode that on this website.
Linux Packages Search: search engine to find packages on a large panel of Linux Distribution. Very useful for your dependencies!
Very good blog with tips for Linux systems.
More links are coming soon...