This fascinating point from JonUdell (: http://www.oreillynet.com/pub/a/network/2004/08/03/primetime.html) :)
Streaming protocols are necessary for live broadcast, but otherwise, plain old HTTP is good enough not only for sequential access, but also for random access. HTTP 1.1's little-known and under-exploited byte range feature makes it possible to jump around in large media files.
This has extraordinary implications for multimedia bloggers, few of whom have access to Helix, QuickTime, or Media servers, but many of whom can post files to web servers that support HTTP 1.1. Suppose, for example, you record a one-hour interview and post it to your blog as a 20MB MP3 file. You needn't do anything special to support random access into that file. It's all in the hands of the client. Some (including Winamp and RealPlayer) will let you move the slider to any point in the file; others (including QuickTime and Windows Media Player) won't.