we just released a a new draft of the
URI Scheme for GSM Short Message Service (the idea is to define
sms: URIs, and when you click on them, you can send an SMS message). the goal is to better integrate SMS messaging into the Web, and hopefully some devices will start implementing this pretty soon (some nokia phones already support it).
the most important aspect of the new draft is that we now completely removed support for the very obscure concept of
Telematic Interworking with SMS messages. SMS defines a way how something that you send as an SMS message ends up as being sent as a fax or as an email or it is even read aloud to a recipient. this part of the SMS specification was never widely supported; phones often do not implement it or if they do, only through completely useless interfaces, and even if you have a phone and you find out how to do it, chances are that your network operator does not support this feature anyway.
the new draft is much simpler, easy to understand and implement, and hopefully will now more easily get through the IETF standardization process. it would be one additional step towards better integration of various media on the web, and another way of how unified messaging can be implemented by browsers.
so while the draft always talks about URIs, it talks about something that most people refer to as URLs. it is simply a technicality that the term URL has been replaced by the term URI, so even though most people still talk about URLs, what they really mean are URIs...