How to Open Open-Document (ODF) Files in Microsoft Office
Users of open-source office suites like Lotus Symphony and OpenOffice know that those programs can open Microsoft Office documents, but what if you're an Office user who needs to open an Open Document Format (ODF) file? You're outta luck, unless you install the OpenXML/ODF Translator add-ins for Office.
These free add-ins for Word, Excel, and PowerPoint enable those apps to open and save their ODF counterparts (which typically have .ODT, .ODS, and .ODP extensions, respectively). They're compatible with Office XP, 2003, and 2007. [via gHacks]