I've been trying to do some uploading of a file generated in flash. After some looking around I found someone out there had a good solution, but it was a bit outdated (because it didn't work me).

It turns out Flash 10 has some updated security features
User-initiated action requirements in Flash Player 10. But after some looking into it, seems like that's

so I've looked some more, and found a class that does this quite painlessly - MultipartURLLoader
found via blog.inspirit.ru