they work by downloading data from the internet via Wireless Application Protocol (WAP). they have a browser built in. You can really only access text-based information at the moment. Whether the services are useful to you depends on your lifestyle - are you on the move a lot? Do you need to keep up with the latest news, sport, share prices, etc. I find I use mine only rarely, when i'm away on business for example and the hotel TV has no teletext i can get TV listings, sports results etc. WAP will soon be superceded by GPRS and eventually UMTS (or 3G - third generation) which will allow much more functionality such as downloading music, graphics, movies, etc.