If you have played with Google Docs a bit, perhaps you have noticed the UPLOAD button next to the list of docs options. This works great to upload from Word, Powerpoint, .pdf, .rtf, or what have you.
What some people don’t know is that you can also convert your Google Doc to a number of other formats as well.
While Doc is open, pull down File (the one on the Docs menu), and choose “Download As” and choose a format.
In my experience, the conversion is very close. Sometimes the font or some pictures need a quick resizing, but this is usually not a big deal.