Dag-Øyvind Paulsen has created a useful service for people who receive Office 2007 Word documents (.docx) and PowerPoint files (.pptx). His service allows you to upload the docx/pptx file to his web server, where the system he has put together will convert the Office 2007 files to classic Office 2003/XP/2000/97/etc. style files (of the .doc and .ppt form).

The services are called, appropriately, DOCX2DOC and PPTX2PPT.

While I suppose one could argue that providing a service that enables you to go backward from a strict technology standpoint is Not A Good ThingTM, there is a market out there for people who:
Don't have Office 2007. Don't want to (or can't) install the respective Office viewers. - Don't want to (or can't) ask the original sender to convert the file and resend it.

So, for those people this is an interesting service.

The creator has automated the conversion process and made it possible to do the transformations online in much the same way Office 2007 allows you to do Save-As and then choose the legacy formats. The service is offered on the honor system: If you use it, you're asked to pay $2 on the page where you download your converted file. Running a system like this costs money, and while on the order of 600 people a day have converted files in the week or so the service has been online, only a very, very small handful (less than you can count on one hand) have paid. If you read this and use the service I certainly hope you'll add to the paid-user count.

The process is rather simple from the end-user standpoint. Browse to the service web page for .DOCX or . PPTX files, browse to find the file on your computer that you wish to convert, choose the output format you prefer (you can choose from the legacy office formats, as well as .RTF, .TXT and .HTM), and then click the resulting hyperlink to download your converted file. It's pretty slick.

Being the security wonk I am, my antennae immediately went up as I thought of business users uploading potentially sensitive documents to the system, where they have to be stored in both the original and converted form for at least some period of time in order for a system like this to work. Dag-Øyvind responded by saying that he agrees, and that he warns people on the web site not to upload private, confidential or sensitive files.

His system appears to be well-secured (I did some quick checking and there is no way to browse for files without knowing the actual filenames) and while the file-naming and identification convention is strong (it uses filenames built up with a date-time value plus a randomly generated GUID, so you have to know the unique and random name in order to access any given file), the ultimate risk on a system like this is the guy who runs it. The files are cleaned up (deleted) from the system automatically every day. But, he says one should realize that since he controls the system, he has the ability to view any and all files up until the time they are automatically deleted. In other words, he's the biggest risk. I like the honesty in that statement. I asked him if the original and converted files could be deleted more often than once a day, and he said they could be and that he would consider doing so.

If you have a need to convert and don't have Office 2007 handy, this might be the right service for you.

Some technical details about how it works are available at: http://www.docx2doc.com/Newbies-Guide-To-docx.aspx