What about posting a bid in rentacoder.com or similar:
"First: generate a page with input field and submit button. If the user clicks on submit, he gets a second page with a link saying "click here." If he clicks on that, he gets a third page saying "you said: ..." where ... was whatever he put in the input field. This has to happen without the value being passed in the url; it should not be possible to change the behavior of the third page by editing the url in the second"
I think that's another programming language evolution to consider.