Here's the use case for our challenge. Let's say you have an App Engine application that generates an XML, text, or PDF files, based on Datasource inputs. The challenge is to send this file to an FTP server. Also, the FTP server on occasion has files that the application needs to pull down and store in Google's.
Luckily wcheung hates martians and reindeer enough (you gotta watch his video!!) that he came up with a solution for our FTP with Google App Engine challenge.
His entry writes items into Big Table and then uses an FTP proxy that he wrote on Heroku to send files to an FTP server. He also uses the FTP proxy to download files from the FTP site into Big Table. Really cool solution! Congrats to wcheung!
Check out his submission video. Not only is it informative but its highly entertaining as well.