Recently I've become more and more drawn to functional programming, reading articles and tutorials about it and about various more or less functional programming languages, such as Lisp, Haskell, Javascript and Scala.
I just finished reading a nice, introductory article about functional programming. It explains some history of functional programming, benefits of it, and concepts like higher-order functions, currying, continuations, pattern matching and closures, in terms of Java.
The author seems to have quite a few interesting-looking articles on his site, thus there's one more site to my blogroll.