Slapp: A simple chat wall Merb tutorial is a perfect example of the sort of tutorial / guide that could encourage a lot of people to try out a new framework (as far as Merb is new, of course). It walks you through the process of developing a "chat wall" type application with Merb from start to finish (right from installing Merb to playing with the running application).

One thing that makes the tutorial stand out is that it puts test spec driven development at the heart of the application. After installing Merb and configuring the database, you're straight into writing a story with RSpec! This is quite different to most of the Rails introductory articles which skim over testing, and it makes the guide very suitable for those who aren't familiar with RSpec but who want to learn how to use it while developing a Web application.

Lastly, the "finished" application is available from a Gitorious Git repository for those who want to work backwards or look at the code up front.