I'm from a C#/.NET background, but have been incorporating more functional programming techniques into my programming in the last couple of years. This, combined with my deepening understanding of the f.p. aspects of JavaScript (after reading JS: The Good Parts) and an interest in Lisp (after reading On Lisp by Paul Graham) got me really interested in f.p., and I started picking up Clojure in my spare time. It struck me as a standardized Lisp with access to lots of great libraries, which overcomes two of the main previous disadvantages of Lisp. I'm hoping it becomes more mainstream in the years to come, as it's a lot of fun to work on, but not something I can make much use of at work, unfortunately.