As David mentioned, I spent some time last week implementing Google Suggest-style functionality for an application for one of our clients. This was the most work I've done in Javascript, so it's been a good learning experience.

There's a lot of talk going on lately about AJAX, and it is an exciting technology with a lot of potential uses. Tim Haines has started an interesting 'blogversation' about AJAX wondering about potential uses of AJAX in an e-commerce environment. Personally, I like what Netflix has done; they've implemented functionality where if you hover over a movie title, you get an expanded description of the movie. Also, their star rating system is built using asynchronous technology. This is an example of what I think a great use of AJAX is; it enhances the user's experience without breaking any expected functionality, such as using the back button.