Almost every bittorrent client has built-in prioritization of files. Do you know if there is a client that allows me to set up priorities inside the single file?
For example, you're downloading an independent free movie, but you have a slow connection. I'd like to tell the BT client to download first pieces of the file first, so I can start watching it, like I could if I were downloading it over HTTP in one piece. i.e. watching while downloading.
If there isn't any, I'll probably have to hack the source code to make this possible. Bittorrent protocol allows this, because my client is asking other clients for specific (although random) pieces. It kind of defeats BitTorrent's design of distributing the rarest pieces first, but with tens/hundreds of seeders, it won't make a difference to me.