Word Reader 5.0 lets you read DOC, DOCX files without MS Office
Basically, Word Reader will let you open and read DOC, DOCX, RTF, TXT, or HTML files. You can't create or edit files. Just open and read them. It handles formatting pretty well, although it seems to have issues importing some images.
Microsoft also offers a free Word 2007 viewer for Windows, but the Microsoft viewer weighs in at 25MB, while Word Reader 5.0 is just a 5MB download. So if you've got limited bandwidth, this could be the way to go.
Alternately, you could install OpenOffice.org or Abiword, or use an online office suite like Google Docs or Zoho Writer to open Word files. Or you could use online file conversion service Zamzar to convert the docs to a format you can read.
[via Technix Update]