docDroid is an interesting take on document conversion. You upload a document in pretty much any format you want (Word, PDF, etc.). Then you email the link to someone, who can then download the document in any format you want. In other words, if you think someone might want to convert your doc, it saves them the extra step of having to go to a different document converter to do so.
I’m adding it to Not “The Best,” But “A List” Of Ways To Convert PDF & Word Documents.