Continuations From Generalized Stack Inspection
Whoa. Okay, so it seems that you can implement first-class continuations using exceptions. Without either putting your call stack on the heap (a la Stackless Python) or rewriting everything in CPS style.
The best part is that unlike the latter two approaches, you only pay the performance penalty if/when you use the continuations.
Clements, Felleisen, Krishnamurthi, Pettyjohn, Marshall, you guys rock.
(Hat Tip: autrijus)