For a while I know about google Docs service. One can upload/create/edit various types of office documents. It has very good compatibility with MS Office and is able to talk OpenOffice formats as well. Once you are done with your editing you can save into PDF file and send to friends.
On line collaboration is of course supported as well, documents can be read-only or shared among friends by sending them invitation email. Besides corporations this means you do not have to have Office tools installed on your PC as long as you have Internet access or you do prefer to have solid and robust OpenOffice installed (free of course). When it comes to corporations, this might not work as some obscure macros are usually deployed in this sphere.
Today when reading about GoogleToolbar 3.0 (still in beta yet) I found out new cool feature. When applied one can throw documents on your browser window and they are automatically opened in GoogleDocs and ready to be viewed/edited. When you have you google account ready, there is even no need to sign in anymore.