The problem with that is that you will probably do a search for something which has never been posted before you make the request. So even when someone meets your request, you change it the next time around. A sort of negative feedback I guess.
I'm not so sure why that is a problem, because in fact, I always thought that was the most redeeming feature of the challenge. It is not that I search for something that has never been posted, but rather that I am tailoring the challenge to each new claimant to prevent exactly what was stated above (pre-positioning posts that they could claim are to meet a challege to go back and post something).
The basis of my challenge is founded upon the presumed claim that someone (a) is a time traveler and (b) has ready access to their time traveling device such that they can go back in the past to meet the challenge.
If this is, indeed, what the claimant is claiming then there should be absolutely no issue with them accepting the specifics of what they need to post from me, hopping into their time machine, going back a couple days, or a month, or whatever, and actually making the post as requested.
In the past (no pun intended), I have even asked claimants to register with a specific, new username so we could see their register-date show up as in the past, and then gave them specifics of the title and content of the post. Of course, none could do it! But I hope you would agree that it is not because the "challenge" is impossible, but rather that we have seen no actual time travelers.
And now I will await all the non-scientific boneheads who will try to (once again) tell me about "infinite worldlines" and why my challenge is not "fair"... The challenge is perfectly fair if one continues to believe the "romantic" notion of a whole person being capable of time travel (i.e. the way it is always portrayed in stories and movies). /ttiforum/images/graemlins/devil.gif
RMT