NeoOffice - OpenOffice.org for Mac OS X has released its first Final Release - if you already use a beta version, you should upgrade, and if you don’t use it, you should try it!
From the site:
NeoOffice/J is a full featured office productivity suite including word processing, spreadsheet, presentation, vector drawing, database, and macro functionality. It can be used as a free alternative to Microsoft Office:Mac. You can exchange documents with Microsoft Office and OpenOffice.org users, even on other platforms!