If you have a place where the landlord will throw a hissy fit if put holes in your walls, wall decals are your friend.

Slick Sticks has a whole bunch of patterns including pac-man, army men, and every kind of dot or square you could ever dream of.  Just place on your wall and peel off after you move out.  I, for one, would go with the dinosaurs which come in 12 colors.

[Slick Sticks - $32]

Tagged:$25-$50, walls