Software Deployment

For starters - this is posted in the wrong forum. You'll do much better to post this in the "Package Development" forum.

You say all your users aren't in active directory, does this mean all your computers aren't in active directory also? That would be my first concern before even thinking about deploying software.

Check out http://itninja.com/link/deploying-openoffice-using-microsoft-group-policy. It is located in the "Package Knowledge Base" on AppDeploy. Once you unpack the the software, by running the setup executable with the /a switch, it becomes a pretty straight-forward msi install. Create a transform (MST) with the tool of your choice - ORCA is free, other tools have more intuitive interfaces, but will cost you some money (trial versions are typically available). Once you have that all set up, copy all files to the server you will run the install from and deploy the software to the machines using Group policy (I'm assuming this is your choice since you mentioned AD in your post). Choose to deploy it with advanced options, and add the MST file in the "Modifications" tab.
For PCs that aren't in Active Directory, you can also burn a CD with all the installation files and your MST and run the setup program in the autorun.inf file. It would look something like this:

[autorun]
open=setup.exe TRANSFORMS=customtransformfilename.MST

You'll have to log on as an administrator on each machine, pop the CD in and let it run. Do yourself a favor though, get all the PCs in Active Directory and bypass the CD install.