Period themes (the 20's, the "roarin' (18)90's" the 70s, any World War) would be cool for Poser and 2D challenges. For more generic challenges, I'd suggest: 1) Future Wars - this could derive from games (Warhammer 40000, Wing Commander, etc.), fiction (The Man-Kzin wars, for example, or Star Trek), etc. 2) Altered Reality - Perhaps Salvadore Dali-esque, or derived from M.C. Escher, or maybe just drug-induced... :-) Just some thoughts... :-)