The best thing to do for now is to install OpenOffice alongside Microsoft Office, if possible. The most recent versions of OpenOffice and StarOffice support the Open Document Format, sponsored by OASIS. But until Microsoft's office suite supports the standard, it won't really be a standard. There is progress, however, the state of Massachusetts had mandated that the format be in place for state systems by 2007.
To see how another expert handles this question, click here.
This was first published in November 2005