Two Nice UI Amenities

Neither of these is particularly new to the web, much less new to the world, but they sure can make life easier:

• The type-a-few-letters-and-it-narrows-the-list-down list. I remember seeing this one in one of the major PC apps in the 80s and going "oooohhh" kind of like the little green men in Toy Story. It hasn't lost any of its appeal. Wikipedia added it to its search field a while back, and it's a welcome addition.
  
• The field-that-remembers-what-you've-put-in-it-previously. This is a standard browser feature (or plug-in), but I remember life without it and I like life with it better. Besides the obvious convenience of not having to type that 20-digit account number over and over again, it helps ensure consistency. The usual implementation is even a bit smarter than I imply: it can remember what you've put in similar fields, possibly in other pages entirely, so it can suggest your usual email address in a new "email" field it sees.
  

The two fit nicely together. If over the course of time you've given several different responses in a given field, it's very nice to be able to just type the first few letters and get the one you want. For example, blogger's tagging feature works exactly this way. Whenever I have occasion to refer to Alexander Stanhope St. George, he's only a few keystrokes away, and I don't have to remember whether it was, say, "St." or "Saint".

This is exactly the kind of small-scale memory that makes UIs more intelligent, and as I've argued before, "intelligence" here isn't just metaphor. The UI is intelligent in the same sense as an animal is. I'll hasten to add that a smart fields like I'm describing are of course not intelligent in the classical AI sense of being able to pass a Turing test. For me, that just says there are more kinds of useful intelligence than being able to converse like a human. But that's a whole other long discussion.

Note that both of these features can be handled either locally (as when the browser remembers addresses you've typed into "Address" fields) or remotely (as with Wikipedia's article titles) [More accurately, the knowledge can be stored locally, remotely or both, and the processing of that knowledge can also happen locally, remotely or both, mostly mix-n-match]. While the basic features don't inherently require AJAX, AJAX can certainly make them more widespread and useful.