Web 2.0 applications are Flavour of the Month at the moment and the WACS architecture is completely compatible with it. However it's easy to say that and quite another thing to prove it, so we decided to create a demonstration application back in wacs-php 0.8.4 that shows how to do it. Our initial application was a dynamic model selector where you click on attributes and the lower half of the screen updates with the models that match the criteria so far. We've recently added a bunch of new features to this including body type, complexion and the full range of model attributes and have re-written it to use the industry standard jQuery library.
You then simply click on the appropriate attribute and the page updates with those models who match that criteria. Click on another attribute and the page updates again with those who match that criteria and so on. In the illustration, the icon we clicked on was for long hair...
This was also the first Wacs-PHP application to use the standard Wacs tools look-and-feel to show that tools using the different technologies can be easily intermixed. We have recently added a partner application to modelsel called setsel which uses similar attribute marks as filters to select sets dynamically based on the criteria you select. We expect to add a few more web 2.0 demonstration programs over the next few Wacs releases.