I can't quite tell if you're serious. Continuations are fun, so I'll post this on the off chance it helps someone.
They are perplexing until they aren't. Model stack frames as independent state. When you return from a function the stack frame can stick around. Now later, place your stack pointer back in the frame that you returned from earlier.
Add a convention for passing arguments when you update the stack pointer as above. Now you have continuations.