One of the best and most helpful online business tools I've used recently is OpenOffice.org.
OpenOffice.org is a free open source project that allows you to create documents, spreadsheets, databases, presentations and more in software that's very similar to Microsoft Office, but without the cost.
OpenOffice is not new -- the project first got started in 2000 -- but I hadn't had a chance to download or use it until recently, when a client I was working with asked me to create a file using the software. If you're familiar with Microsoft Office (or with Google Docs), I think you'll find it very easy to use.
If anyone else is using OpenOffice, I'd love to hear what you think!