We tend to have a weakness for the way wall decals add instant, affordable detail to an otherwise plain surface. Even better still,
Ferm Living makes a few styles of removable all-black stickers designed for walls that have an element of utility too.
Their world map may not be the most detailed of geography lessons, but at least provides a handy reference for conversations about world affairs. A calendar and to-do list turn any blank wall space into a way to keep organized, while the stickers based on the periodic table (another soft spot) offer some rudimentary lessons on elements and their symbols.