His path is not dissimilar to mine except that I had the good fortune to get hooked on dynamic languages early on, which is possibly why I have been slower to get from B to C with Lisp (less need when you can implement many list based and functional idioms in Perl).

I almost want to like Smalltalk more than Lisp, but I suspect that is because of the OO ingrained in me and also my worship of Xerox Parc, Douglas Engelbart, etc. My gut instinct, however, tells me that Lisp is just that one level higher.

I'm very interested in any languages/dialects that implement the power of Lisp with less noise. I'm sure it's possible, but it just hasn't been "discovered" yet. On the other hand, perhaps it's not. Perhaps the endless, nested, streams of braces and symbols are the purest representation of code. Like logic DNA.

Update: In Arto's post he mentions the Lisp machines. I would suggest that in a not dissimilar way that Squeak is a software embodiment of the Alto Smalltalk Machine, Emacs is a rough embodiment of a Lisp machine. Some people even use Emacs as their entire windowing system.

Wikepedia has some information on the history of this puzzle. Excerpt:

The Zebra Puzzle is a well-known logic puzzle.

It is often called "Einstein's Puzzle" or "Einstein's Riddle" because it is said to have been invented by Albert Einstein as a boy, with the common claim that Einstein said "only 2 percent of the world's population can solve this". It is also sometimes attributed to Lewis Carroll. However, there is no known evidence for Einstein's or Carroll's authorship.

There are several versions of this puzzle. The version below is quoted from the first known publication in Life International magazine on December 17, 1962. The March 25, 1963, issue contained the solution given below and the names of several hundred solvers from around the world.

The version of the puzzle given in Wikipedia is tougher because two pieces of information are missing. Naturally someone has already written Prolog and Lisp solutions for it :)

I learned an amazing feature of the dired mode, that with the command wdired-change-to-wdired-mode command you can make the directory view editable. Eg. if you do a search and replace in the buffer (using normal commands), the files will be renamed. Cool!

There's also a neat emacs lisp fragment to keep an eye on open memory allocations in your Objective-C code (Define your own keywords). Mind you, I can't wait for the Objective-C garbage collector that will be standard in OSX 10.5 :)

Possibly the most useful productivity addition (especially for an emacs-using team - if I can find one these days...) is linkd.el which allows you to embed internal and external hyperlinks in emacs so you can, eg, put links in your code comments to relevant files, sections, or web pages.

Update: For GTD (Getting Things Done) fans out there, I linked through to a page on using the emacs org-mode for implementing GTD. By an Australian no less :)