Office 2007 / DOCX files got you down?

Recently a few people have asked me how to open DOCX files, which are created in Word 2007 / Office 2007. I have found 4 solutions so far:

1. Microsoft Office Open XML File Format Converter for Mac is perhaps the canonical solution. It won't make new Office 2007 documents, but I haven't tried doing that in the other solutions either.
2. NeoOffice 2.2.4-Patch 3 is known to open at least some non-trivial DOCX documents. NeoOffice only runs on Mac OS/X.
3. OpenOffice 3.0 can now open Office 2007 files, but I haven't tried it. OpenOffice runs on Windows and Linux, as well as other platforms.
4. iWork '08 seems to open these documents. Again, iWork only runs on OS/X.

A "Word" about Microsoft's converter. The article links to the Mactopia downloads page, which is organized by category, and by default shows the "latest" new power toy available. To select other tools, you use the menu at the bottom. Currently, the converter is filed under the "Additional Tools" category, and the tools in that category are revealed only when you click on the category name. So, it will appear at first that you are taken to the wrong page, but it is in fact the right place.