The article includes the SwfUploadComponent as well as usage tips. I developed this component because I needed to handle uploads which could be associated with any number of objects in Mango. One of the key goals of Mango is to be user-friendly, and since file uploading is one of the least fun experiences on the Web (in my opinion, anyway), I needed to find a way to at least simulate the kind of user interaction that the desktop operating system offers. SWFUpload meets that need.
I’m working on a project page for SwfUploadComponent which will have the API for the component. Stay tuned.