$ apt-cache policy pidgin
pidgin:
  Installed: 2.4.0-1
  Candidate: 2.4.0-1
  Version table:
 *** 2.4.0-1 0
        925 http://ftp2.de.debian.org lenny/main Packages
        400 http://ftp2.de.debian.org sid/main Packages
        100 /var/lib/dpkg/status
     2.3.1-2~bpo40+1 0
        575 http://www.backports.org etch-backports/main Packages