Uploads are now allowed
You should choose the folder concerned, (including the version if applicable). Add a description and tags and hit the upload button.
Files are moderated, so they can be checked for content, viruses, etc, so be patient when you upload them.
You will not be able to delete or edit the entry once sent. (If you need to PM the admin).
There is a 12mb limit and some folders only allow the correct file type (e.g Excel 2007 workbooks only allows .xlsx, .xlsm, .xlsb and .zip). most allow .zip so if your file is large, that would be a great way to go.
Hope this gets some great free demos, add-ins, etc being uploaded