If you are using Office 2011, the PowerPC message is erroneous. Office 2011 runs on Lion just fine.
If you actually mean Office 2004 or Office v.X, then you'll need to upgrade to Office 2008 or 2011 or use one of the alternatives to Office, like OpenOffice, NeoOffice, or LibreOffice.
You can also open most of them in iWork or as Niel pointed out, TextEdit.
I upgraded to Lion and now I can't access my microsoft word for mac 2011 documents because PowerPC is no longer supported! Now what?
If you are running Office 2011 then you CAN open all those docs. Just double check your compatability settings in Office Preferences. If it is 2004, then it's a whole different matter