Here is your challenge. You need to teach newbies how to build a webapp in a day. You need to teach them in a day and on the second day they need to build an app individually. These apps should be simple but should be useful. So variations of “Hello World” won’t do.
When VB came out in 1991, it set the standard for writing simple Windows apps in hours. You could easily teach some one how to build a non trivial application in a day. You dragged and dropped a few components on a form, wrote a few event handlers. In later versions, you had the ability to seamlessly connect to databases. You just worked with one tool and had an app. You could either build a desktop app with Access database or a client server app with enterprise class databases like SQL Server, Oracle etc.
Then web happened. We went back to terminal style submit mode and interaction disappered, for a while. A few years later interaction came back, first with Ajax and later with libraries like jQuery and RIA like Flex and Silverlight. However, to build even a half decent app you need to know HTML, CSS, some server side programming (PHP, Python, Ruby, Java, C#). If you want to do a decent clean app, you need to know some MVC based web frameworks like Ruby On Rails or Django or Zend etc.
Simple apps should be simple to build with bare minimum skills. It will be nice to have one web based application authoring tool where you can prototype apps by dragging and dropping a few components, creating a form, writing some code in your favorite language and launch with a click.