If a flash movie (.swf) is looping in a client browser, is this attached to any process running on the webserver? I assume that after the client downloads the file, it starts to play and also frees up the webserver, meaning that if several clients are playing a movie at the same time, this will not affect new sessions. Is this true?
Flash movies do sometimes get cached by the webserver - the side effect being sometimes the file on disk doesn't match the file that gets served out. If your webserver supports content expiration for that file you might like to turn it off.