Some type of commercial application is made by Adobe some time before, try looking at Macromedia MX Server, at his macromedia.com site.
And get into developers zone, where they told you about this.
A php solution it could be acceptable with a upload form for the video that allows .avi files, allow maximum weight of the file, postprocessing this file before to avoid sending suspicious files like virus, or trojans, backdoors... detect some frames of this video and put on a public space of the registered user, not hard to do, but laborious on treating the multiple type of files.
😉
And adding into FLASH, there is some php classes (i dunno remmember yet) that allows you to "convert" (more exactly fits) into the swf file that could be streamed.
Refered web -> like google.video or youtube.com
But please, think that this consumes a lot of bandwidth, and you have to do some type of balancing by hardware (alteon) or by software php that allows to access one or other server less charged.
Regards !
