The package pst-pdf simplifies the use of graphics from PSTricks and
other PostScript code in PDF documents. As in building a bibliography
with BibTEX additional external programmes are being invoked. In this
case they are used to create a PDF file (\PDFcontainer) that will
contain all this graphics material. In the final document this contents
will be inserted instead of the original PostScript code. The package
works with pstricks and requires a recent version of the preview
package.