Over on the TiVo forums (www.avsforum.com) a number of
TiVo owners with Telewest DiTV1000 STBs have now
received the dongle which allows the TiVo to control the STB. As the Pronto can control the TiVo, there is
now one (expensive) option!

As far as I know the dongle (£30) only works with the TiVo unit and is not a generic standalone device.

As we've been thinking about getting a TiVo anyway it looks like we'll be spending some money soon!