You use Word, Excel or PowerPoint on your computer to create your office documents, but you happen to use Google Docs to create and store documents online and share them with others. With a simple free plugin, you can save your work done with Office 2003, 2007 or 2010 online on your Google Docs account.
Once the plugin installed and properly configured, your documents will be automatically saved to your Google Docs space at the same time as you save them on your computer. This will give you a backup copy of all your documents online.
Your documents will be accessible from anywhere (a web browser is enough to access Google Docs) and you can share them with your colleagues and recover your computer in case of data loss.
To use Google Docs, you just need a Google Account used as Gmail, Picasa Web Album, Calendar, … If you do not, you can easily create one for free. Note that Google Docs allows you to store up to 1GB of free documents.