HTTP File Uploads in PHP
And by this I mean uploading files from a PHP script to another HTTP URL, essentially submitting a web-form with a file-field from PHP. I needed this in Organik, it took me some hours to find out how. My hacky result is here for the world to reuse:
http://github.com/gromgull/randombits/blob/master/http_file_upload.php
Enjoy.