One way around this is to edit the Setup.xcu file (easiest way to find it is to search in the OpenOffice install directory, as the typical location is C:\Program Files\OpenOffice.org 2.1\share\registry\data\org\openoffice), and modify it as follows:
<prop oor:name="ooSetupConnectionURL" oor:type="xs:string">
Once that is done, locate the quickstart.exe program in your openoffice installation. Drag that to your Startup folder. Voilà, you have an OpenOffice running in the backgroung, AND you can edit your files.
So you can keep the true service installation for your production servers.