I can”t say it better than the Open Office team, so:
Introducing new functionality with OpenOffice.org 2.3!
OpenOffice.org 2.3 is available for download now! It includes several new features in addition to the usual improvements to stability, performance, Microsoft Office compatibility and Accessibility. Some of the new and exciting features are available as free extensions which increase OpenOffice.org functionality.
The use of extensions to increase the flexibility of OpenOffice continues the theme of extension and plugin use that is utilised by a number of open source programs, including Firefox and Thunderbird.
Visit the OpenOffice Extension Repository to download and install extra functionality in OpenOffice. I”m particularly interested in the OpenOffice.org2GoogleDocs extension – I”ll try it out and let you know!