Is there a site that will (ideally for free) convert a file that I upload to a PDF? Just general office formats, nothing fancy like CAD or other graphics formats.
Google Docs is great for this.
You can upload a number of formats, and then edit the files etc.
When you're ready to get the PDF, just do File -> Download As -> PDF
Zamzar allows for conversion of most (office) documents into other popular formats. Its free for filesizes upto 100MB
My personal solution to the conversion question is to install a PDF printer like CutePDF (for Windows, such functionality is built-in to Mac OS X), set that printer as my default, then right-click and do a "Print" form the context menu in Windows Explorer.