One of the most awaited features has been added to Google Docs - support for MS Office 2007 formats, namely .xlsx and .docx. They appeared in the
list of supported formats , which already includes .doc, .odt, xls, .ods, .ppt, .csv, .html, .txt, .rtf and others.
Import of documents in new-fangled formats occurs in a standard way, through the “Upload” menu. The system will automatically determine the format of the document and import it into the database while preserving all the formatting.
')
If you need to convert hundreds / thousands of files, this can be done using the
Google Documents List API .
via
Google Docs Blog