Perhaps one of the most useful AJAX applications I have seen is the ability to have stock prices update in real-time such as this page on MarketWatch.com. This is the sort of application that differentiates itself from Web 1.0 and makes the web a more useful place. Others have commented that there is an arbitrary distinction in the 2.0 moniker and this is true -- and I say this is the point, and a good one at that. The Web should evolve and get better constantly and sometimes artificial numbers, terms and acronyms like AJAX (not a new technology but a new acronym) are needed to get us up and going towards global improvement of an already pretty amazing Internet.