µTorrent mUI (mobileUI) is a plain-text mobile version of the WebUI with most of the important µTorrent functions. You can start, pause, stop and monitor your downloads, and it also offers some additional info about every Torrent and a couple of settings. µTorrent mUI is a web app which will allow users to turn their iPhone or any other mobile phone supporting GPRS and a web-browser into a remote control for the best Windows Torrent client µTorrent.
* mUI requires a mobile with internet access and µTorrent with WebUI enabled.
You can also use the amazing Opera Mini that works on any mobile with java. And of course it works on iPhone, but not optimized for it yet.