Instead of downloading that attached Word document, especially if it's "a keeper", you should try opening it with the brand new Gmail feature available today. It lets you import any attached Microsoft Word document directly into Google Docs with a single click. The "View as HTML" option still exists, but should probably only be used for documents you intend to view infrequently.
The new feature has difficulty showing embedded images correctly for me still, but if that's a common problem it will likely be fixed in very short order. Other than that, the import process is smooth, and I am very happy with this new interoperability.
When spreadsheet attachments were given the same treatment in Gmail on November 2nd, it was only a matter of time before Word documents had something similar.
I wonder if Google Docs will have support for PDF documents soon? The Google Books interface would be an excellent alternative to Acrobat Reader if you ask me. Once they add this feature to Google Docs, which I am sure they are working on, viewing attached PDFs in Gmail through this service will not be far away.