I use Lisp
Well some people have been slagging off my use of Lisp so here's something special for them!
All logos are from the Public Domain Lisp Logo Set By Conrad Barski, M.D. who says "Why an Alien Lisp Mascot? To most programmers, Lisp seems like an entirely alien language at first. One thing that I think the Lisp community has failed to do is convince other programmers that this strangeness is not an arbitrary obstacle, but a necessary adjustment that imparts great power to programmers that would otherwise be unattainable. The alien Lisp mascot and quirky logo designs are designed to accentuate the awesome (and, to most people, alien) power that Lisp languages have. At the same time, they show how fun Lisp programming tends to be and that Lisp has wide appeal far beyond the stuffy academia it is sometimes wrongly associated with."
Its also apt as LispWorks 4.4.6 Personal Edition is now available for Linux, Windows and Mac OS X.
Just to show the power of Lisp in a current development practise read about using Lisp for Domain Specific Languages.