This version of pst-barcode uses the xkeyval package, the extended
version of keyval.

Save the files pst-barcode.sty|.tex|.pro in a directory, which is part of your 
local TeX tree. pst-barcode.pro should be saved in ../texmf/dvips/pstricks/
Then do not forget to run texhash to update this tree.
pst-barcode needs pstricks, which should be part of your
local TeX installation, otherwise get it from a CTAN server, f.ex.
http://www.dante.de/CTAN/graphics/pstricks/