I’m quite impressed with facebook. Its clean, doesn’t make us old ppl feel out of place, i’ve been ‘automatically’ connected to people i haven’t been in touch with for a long time!
From a techie point of view, i marvel at how they’ve used AJAX in their pages. Makes everything feel so snappy. We use AJAX in my company’s product, but I’ve never worked on that side of things and am looking forward to learning that stuff.