AJAX is the new web-application programming paradigm being widely espoused by the Web 2.0 techolytes; I’ve been looking at some of the stuff using it and they are not too shabby! (from a functional perspective, anyway). Google Mail, and Google Calendar are some of the more well known ones, but look at Goowy and Fold as well, if you want to see some additional offerings. It appears to be relatively easy to toss together an AJAX application using the prefab frameworks available for PHP, Java and even .NET. So the next question is…what to build?