C3ntaur's Journal: What to do with OOXML files?

I just received my first OOXML file. I can't open it because I have not shelled out for Office 2007 -- and I had no plans to. OpenOffice is unable to open it and from what I've seen, the import filter is still a ways off.

I replied with a quick note to the sender that I can't open the file, but I'm not sure how my response will be met. After all, the sender paid good money for his shiny new Office 2007, and is not likely to downgrade nor to bother with saving in "inferior" formats. I'd like to put it to the community then: how do you plan to deal with the coming onslaught of OOXML files?