Lisp Macrology

Post crazy Lisp macros you've written in this thread.

I'll start off with a quick one I wrote 15minutes ago, PROGK:

>>12
Isn't that what all the other macros posted in this thread do, in one form or another?
However, there is no jumping, all forms are evaluated, and the value(s) of the k-th form are returned. If you just jump to one of the forms, then it would have different semantics (prog* forms are usually used for side-effects, jumping would change the semantics). It would be easy to do it by using a CASE or COND form.