Microsoft Office Web Apps are convenient online companions to Word, Excel, PowerPoint, and OneNote that give you the freedom to work with your Office documents from virtually anywhere with a supported browser.
And most importantly this is FREEE !! It’s a light version of Office offered free of charge by Microsoft over the internet. If you have access to Windows Live Skydrive which gives 25GB of storage then you will be able to create Word, Excel, PowerPoint and OneNote documents.
You can access Web Apps through http://office.live.com by providing a Windows Live ID you will gain access.
The documents that you create will be stored in your Skydrive through which you will be able to manage it and share it with your contacts.