[whpalmer4]

Click on the iPad in the sources column. Then click on the Apps tab, and scroll to the bottom of the window. You'll see another list of Apps, namely those whose files you can sync, including OmniFocus. Select OmniFocus, then select OmniFocus.ofocus in the right hand pane, then click Save to... button at lower right to choose your destination. Doesn't even have to be done on the machine you normally use to sync the iPad, either.

Once you've downloaded the file, you can extract attachments even without a copy of OmniFocus for the PC (fortunate, as none exists!) by drilling down into the OmniFocus.ofocus directory.