What Lisp should I learn?

I already know Scheme (read SICP, took the class, got an A, wrote a logo interpreter in Scheme, wrote a Scheme interpreter in Python, etc.) but I haven't touched it much in two years. It seems to be great for computation, and I can certainly see where it would be a perfect fit for artificial intelligence, but I can't imagine using it for applications or even simple scripts.

So tell me /prog/, what Lisp dialect should I learn or at least what are the pros and cons of each?

>>2
Thanks. I was actually going to mention that I was interested in Clojure's Java integration, mainly because I heard of people developing for App Engine by leveraging the Java API with Clojure and I wondered if the same thing was possible for Android. Dealing with Java is big demotivator for me when it comes to Android development and Jython isn't available for that platform. Since I'm not part of the Lisp community, I'm not sure if Clojure is just a fad/toy-language or if Common Lisp is more established. I noticed that Peter Norvig wrote a 1000-page book about AI with Common Lisp which seems interesting. Scheme seems very good for the type of computation associated with AI (basically, lots of linear algebra with large vectors and matrices), but what you do with that data seems better suited for something else, so maybe that something is Common Lisp.

Well thanks for your input. Keep it coming /prog/.