In my mind, this is one of the niceties of Smalltalk over Scheme...
  there are no special forms.  If the parameter is a block, it
  evaluates to a BlockContext (or closure... hopefully, someday)

Well, Scheme doesn't require special forms. It's just that a closure
in Scheme is less tidy than in Smalltalk!

  | z |
  z := 0.
  [ :x :y | z := x + y + z]

vs.

  (let ((z 0))
    (lambda (x y) (set! z (+ x y z)) z))

Scheme has that wordy "lambda" keyword. Here's how a boolean based on
closures would look in Scheme...

  (define true (lambda (trueBlock falseBlock)
                 (trueBlock)))

  (define false (lambda (trueBlock falseBlock)
                  (falseBlock)))

  (set! boolean (compute-true-or-false ...))
  (boolean (lambda () (do-this-if-true ...))
           (lambda () (do-this-if-false ...)))

Not as tidy as Smalltalk! Smalltalk is a nice *semi-functional*
programming language! Objects and functions are *very* similar!

-- 
Patrick Logan                 mailto:patrickl at gemstone.com
Voice 503-533-3365            Fax   503-629-8556
Gemstone Systems, Inc         http://www.gemstone.com