I only know Lisp and absolutely love working with it and the results we're getting with our web application (I was not a CS major), but my partner who is a Software Architect by profession tells me that programming in Lisp takes about half the code and effort of Java with more impressive results. (See Paul Graham's essays on Lisp: http://www.paulgraham.com/lisp.html)

If you are going to learn a language, learn the most powerful and efficient language you can find so that you can reach your goals faster. As far as I can tell, until ARC comes out, that language is Lisp. A lot of people complain about the lack of Lisp open source out there, but in fact, our application is loaded with great open source Lisp libraries. See: http://news.ycombinator.com/comments?id=20010 http://news.ycombinator.com/comments?id=12619 http://www.google.com/search?q=site%3Aycombinator.com+lisp http://www.cliki.net/index http://common-lisp.net/