Yup, it's a great way to review a lot of commands without reading every man page.

Want to find all the tools on your system that use the curses library (for user-friendly interfaces)? Try this:

  for i in `\ls /bin/* /sbin/* /usr/bin/* /usr/sbin/* | sort -u` ; do ldd $i 2>/dev/null | grep -q curses && whatis `basename $i` ; done | grep -v 'nothing appropriate'

Don't know how your current path finds a program? Use which:

  pwillis@zippy:~$ which df
  /usr/bin/df
  pwillis@zippy:~$ which mount
  /bin/mount

Annoyed that /sbin and /usr/sbin aren't in your path? Use whereis:

  pwillis@zippy:~$ which ifconfig
  which: no ifconfig in (/usr/local/bin:/usr/bin:/bin:/usr/games:/usr/lib64/kde4/libexec:/usr/kerberos/bin:/usr/lib64/java/bin:/usr/lib64/java/jre/bin:/usr/lib64/qt/bin:/usr/share/texmf/bin:.)
  pwillis@zippy:~$ whereis ifconfig
  ifconfig: /sbin/ifconfig /usr/man/man8/ifconfig.8.gz /usr/share/man/man8/ifconfig.8.gz /usr/X11/man/man8/ifconfig.8.gz