Find out stuff about your system from bash

Another post in the "no X server"-section - find out useful stuff from a shell:

• kernel? uname -a (thanks, DaWuzzz)
• How long has the machine been running? uptime
  
• Who is logged in? finger
  
• Short general information (hardware, kernel): sysinfo (package hxtools)
  
• Which distro am I on (for remote administrators or extremely confused users)?
  ls /etc/*-release
  less /etc/<thedistro>-release
  (more information here)
  
• Did I install this package? rpm -qa | grep -i <any part of package name> (you need grep if you don't know the exact package name: rpm -q doesn't like wildcards)