Venkat Subramaniam explains what DSLs are good for, then he demos the creation of a DSL in Java, starting with a grammar and a parser, with an emphasis on useful patterns to be used along the way.
http://www.infoq.com/presentations/Creating-DSLs-in-Java-Venkat-Subramaniam

In this presentation recorded at QCon London 2009, after a short introduction to DSLs, Scott Davis plays with the keyboard showing how to approach the creation of a DSL by typing working snippets of Groovy code that get executed in front of the audience.
http://www.infoq.com/presentations/Writing-DSL-in-Groovy-Scott-Davis

Easyb is a new and very hip behavior driven development framework for Java. This talk will go through the basic principles of Behavior Driven Development, and look at how it builds on and differs from “traditional” Test-Driven Development. It then moves on to look at easyb, a very cool DSL-based behavior driven development framework for Java that uses Groovy to let you pretty much write tests that document themselves.The talk will be very practical. We will look at how to write basic easyb test stories, how to use fixtures in …

Domain Specific Languages or DSLs are languages that target a specific kind of problem or domain. We’ve had various degree of success with DSLs, over the past several years, in narrow areas. However, DSLs are not widely used in general purpose application partly because the popular widely used languages today do not make it easy.
In this presentation we will introduce DSLs, delve into their benefits. We will look at a number of examples as to how we can utilize them for common application tasks. We will take a look at …