The web browser is a kind of meta user interface in the sense that each webpage describes its own UI. The browser supports certain features, such as rendering HTML and CSS, also adds some meta navigation with its back / forward buttons and bookmarks, and adds some meta interaction interface with its mapping of mouse clicks and keyboard shortcuts to interactions with webpage features.

So, (playing a lot with my new mobile phone) I am thinking about mobile and other devices as meta navigation interfaces for a range of functions / features. And, also imagining then that these functions and features could be portable and transferable between devices.

For example, a lot of devices use or could use address book features. My cell phone does, and I see similar features on Palm handhelds. In the future, perhaps our mp3 players will have address books as well to account for tracking which songs our friends (e.g., listed in our address book) are listening to this week.

The address book could practically be the same between these physical devices, but the physical interface on certain devices is maybe better than on others when it comes to editing and managing addresses. Imagining the same address book being portable between these devices, they become more like computers with different kinds of "keyboards", plus, of course, some distinct hardware extras.

So, I was imagining: what if a wide range of electronic / computer device functionality was basically conceived of in terms of something like web browser meta navigation, and any physical device (e.g., computer keyboard, phone push buttons, DVD player remote control, etc.) basically provided a physical interface for accessing that.

(Note: I can imagine that both the Java folks and the Windows folks have been thinking about this for a while. I guess I am just getting hip to it.)

Ultimately, one could own a "mobile phone feature" that is relatively device independent, and that one could transfer from a physical mobile phone interface to a physical mp3 player interface. Obviously, those physical devices both would need to support things like wireless connections, but the user would simply use whatever device interface was most convenient at any time.

Going for a jog: take your mp3 player with the mobile phone feature just in case. Not great for making a lot of calls, but handy in case of an emergency.

Going to your day at work: take your mobile phone with the mp3 feature installed. Not great for storing and managing lots of music, but good for having music on the commute.

Get home: move your mp3 feature and mobile phone feature into your desktop computer, and use it to interface with those features for managing your music, address book, etc.

I guess this kind of thing will happen as some standard operating system-like APIs emerge across many types of devices. But, I was thinking about it more along the lines of webpages that load into a browser, and maybe certain plugins are installed (e.g., the way a webpage can be coded to include data in a Flash plugin, and webpage-like application could use a mobile phone or mp3 player plugin).

Maybe what is most interesting about the browser and webpage model is the way it handles plugins / content types it can't properly render / execute. Maybe device / feature portability is more about designing for graceful degradation (i.e., between one device and another) than about standard APIs?