Wel, Sharen, we've been doing them for a while now, but "my" new idea (as I said, based on how the Challenge Arena and Bryce forums do it), is to include voting, and a winner. The winner gets the "prize" of setting the theme for the following month's challenge. Up above this forum, in tat little box which has all the links in it, will always be a link to the Challenge which is current: rules, motif, etc. You can see above where Varian has posted his "Getting Primitive" challenge, by clicking on the link of the same name. :)