We have a client that wants to use OpenOffice documents in SharePoint 2010 and have much of the same experiences. Does anyone here have experience with OpenOffice and SharePoint 2010? Are there any extensions for SharePoint 2010 that make it work better with the client and WebApps?
If I understand you correctly, your client wants to use OpenOffice documents with Microsoft Office on the Windows XP/Vista/7 client computer or with Microsoft Office Web Applications.
To make SharePoint recognize OpenOffice documents you could modify the docicon.xml file (see http://msdn.microsoft.com/en-us/library/ms463701.aspx) to force OpenOffice documents to open with Microsoft Office on the Windows XP/Vista/7 client computer.
As for the Microsoft Office Web Application I haven't tried them myself but suspect it is a similar approach.