For simple offline playback of mp4 files I usually recommend QuickTime Player, the mpegable DS decoder, or VideoLan. I don’t think the mpegable DS decoder supports streaming, but I think the mpegable player does. I don’t know whether videolan or quicktime player support streaming though.
mpegable player or ds decoder: http://www.mpegable.com
Thank you for this! I also recently found some pretty cool sites like Pitchfork and Indie Train that are comprised of up-and-coming independent artists looking for broader exposure. You can stream MP4 videos while browsing the sites.. they may not offer all the “latest music” but they do offer a safer alternative to streaming. http://www.real.com/resources/streaming-mp4-music-videos