RPM

Find out the version number of an installed package
rpm -q Blahblah

Get a list of all installed packages
rpm -qa

Find out to which package a file belongs
rpm -qf /home/dirk/bla.ttx

Display information about the specified package:
rpm -qi rpm

Show the files that will be installed for the specified package file:
rpm -qp1 bla.rpm

Listing the files in a package file
rpm2cpio logrotate-1.0-1.i386.rpm | cpio -t