You can GREP the files in /var/log/packages to get a listing of the packages. Use the '-l' (lowercase 'L') switch if you just want to list the package name (and not all the files).
Code:
saul@tesla:$ for i in noatun juk kscd;do grep $i /var/log/packages/* -l;done
/var/log/packages/kdeaccessibility-3.5.6-i486-3
/var/log/packages/kdeaddons-3.5.6-i486-3
/var/log/packages/kdeartwork-3.5.6-i486-3
/var/log/packages/kdebase-3.5.6-i486-3
/var/log/packages/kdemultimedia-3.5.6-i486-3
/var/log/packages/kdeutils-3.5.6-i486-3
/var/log/packages/kdevelop-3.4.0-i486-3
/var/log/packages/amp-0.7.6-i386-1
/var/log/packages/kdeaccessibility-3.5.6-i486-3
/var/log/packages/kdebase-3.5.6-i486-3
/var/log/packages/kdemultimedia-3.5.6-i486-3
/var/log/packages/libnjb-2.2.5-i486-3
/var/log/packages/kdeaccessibility-3.5.6-i486-3
/var/log/packages/kdeartwork-3.5.6-i486-3
/var/log/packages/kdemultimedia-3.5.6-i486-3