For OpenERP there is a new modul report_webkit (old name: c2c_webkit_report) avalible. Really great stuff.
If you want to use this on your Server. You have to install wkhtmltopdf. If you are runnung Ubuntu or Debian dont use the package from the reposetory becouse this need a X Server. Instead install a static build. In the other case you will get a IOError.
Hint download: http://code.google.com/p/wkhtmltopdf/downloads/list
A other solution is to hack the OpenERP modul and run wkhtmltopdf with xvfb. This is not the best workaround.
Other possible solution: You can aktivate the debug mode an create a pdf by the client.