I'm a big fan of automated testing/unit testing.  However, it seems that 
there is no widely-used testing framework for Emacs Lisp yet.  I've 
tried various packages (regress.el, elunit.el, elk-test.el, XEmacs' 
test-harness.el, the code in slime.el, and cc-mode's tests), but they're 
all either too simplistic, very specialized, or not very Lispy.

Here's the code that I use at the moment.  It requires Emacs 22.

Please try it out and let me know what you think.  Something like this 
really ought to be added to Emacs.

Christian.