Extending the web to your telephone
Dan Connolly of the W3C has created telagent, an HTTP agent for placing and receiving telephone calls.
The basic idea is that a web browser should handle tel: URLs a bit like mailto:, open up a dialer and offer to call a number. Connolly's solution also works the other way: recording the caller-ID of callers and giving you the option to answer or dial back with a single mouseclick.
The agent, a Python script controlling a modem, works like a web server. HTTP GET and POST requests control its operation. The idea being that you can set your browser up to proxy tel: URLs to this mini-web server. One of the main problems experienced by Connolly has been getting the Netscape web browser to properly proxy though, although he has created a workaround.
For those interested in playing around further with the concept of connecting more communication schemes into the Web, read some of Connolly's draft notes on Real-Time Resources in the Web: IRC, Telephone, Instant Messaging.