The features of the iPhone UI for uTorrent are nowhere near those of the regular WebUI, but it does run smoothly on any iPhone. It requires the uTorrent WebUI to be installed in order to get it running, detailed installation instructions can be found at the iPhone UI homepage.

If you want to run uTorrent on a mobile phone other than the iPhone you could give uTorrent mUI a try. It looks less sleek than the iPhone UI, but the interface will allow you to remotely control your torrents from just about any mobile browser