I just ran across an interesting article series that IBM sponsors: Crossing Borders. The stated purpose of this article:

The Crossing borders series looks at how non-Java™ languages solve major problems and what those solutions mean to Java developers today. This article explores continuations, the technique behind frameworks like Smalltalk's Seaside. Continuation servers make it much easier to build Web applications by offering a stateful programming model without giving up the scalability inherent in statelessness.

This article is from Bruce Tate. Good stuff.