ImageShack is now offering free TorrentFlux-like hosting. Basically, TorrentFlux is a web based bittorrent client that runs on web servers, and it is controlled by using web browser. The download will continue even if you shutdown your computer. After the downloads finished, you can download the files via HTTP or FTP.

To run TorrentFlux, you are likely need a powerful web server, usually the dedicated server which is expensive to ordinary user. There are also commercial TorrentFlux hosting services available for a price.