Hey Indy, how about this since you want alot of posts....do like the "10th caller" type of contest. You and the Mrs. pick a secret# like say 563, give a start date & time for the contest, and then put up the start post. Whoevers post is the # that you two had chosen, wins. You'd have to have a rule like you can only post once every 23 posts, or something like that.
"Congratulations! Your are the 1053rd post! You win! Merry Christmas!"