If you're itching to download a torrent at school or work, where you are not authorized to install any software, you can use this web-based java bit torrent client. This is so cool if you just want to download only one torrent at a time. All you need is Java Virtual Machine.
Here is the snapshot of Bitlet download in progress.
Quote from torrentfreak : It’s not a replacement for the regular BitTorrent client, but it sure is a great addition.