Where is KBarcode for KDE4? Well, there are porting efforts under way in SVN, but these are sadly far from completion.
If you just want to create barcodes easily and save them as image or a PDF, rescue might be near in the form of KBarcode4-light. KBarcode4-light is a simple barcode generator for KDE4. It supports many 1D and 2D barcode formats and can export them as images or PDF files.
It is similar to KBarcode for KDE3, but less powerful. KBarcode4-light allows only to create single barcodes. As the port for KBarcode is not yet ready and no one knows when it will be ready, KBarcode4-light provides basic barcode generation for KDE. An additional benefit is that it provides an easy to use interface for Barcode Writer in Pure Postscript.
It is written in Python using the amazing PyQt4 Qt bindings and based on Barcode Writer in Pure Postscript by Terry Burton.
KBarcode4-light downloads are available. It requires Python and PyQt bindings for Qt4, as well as Ghostscript in your PATH. Please submit any feedback to the KBarcode mailing list.
UPDATE: Due to a small bug, a new fixed version 0.2 is available for downloads.