digiKam is one of my favorite application in KDE since i can use it to export my photos to Facebook directly and it has a lot of interesting features. Unfortunately, this package is not yet part of Slackware default packages, but it's still available on SlackBuilds project.
Another problem is that the maintainer hasn't updated the SlackBuild script to the latest version (2.5.0) and stuck at 1.9.0 up to now.
For those who wanted to try the new digiKam, you can download the original SlackBuild for digiKam from SBo package and replace the .SlackBuild script with the modified SlackBuild from my Box.net account and also a patch file to make it compilable. Put them in the digikam directory and start your engine to compile.
Please read the requirements for the new digiKam package as it adds more dependencies in the process.
Update (April 18): For you who have upgraded to Slackware-Current per March, 26 or newer (GCC 4.7.0 and Boost 1.49), please refer to my updated post about digiKam 2.5.0 and GCC 4.7.0. The digiKam SlackBuild has been updated and now it has two additional patches in order to build this package.