a hinged full length mirror from IKEA (Stave mirror - that is x hides jewelry storage -- brilliant idea from The Girl on the Go! I would use a thin sheet of plywood cut to fit behind the mirror so I don't put so many holes in the wall.
I love full length mirrors because they help fill awkward corners and nooks, but they also make small spaces feel bigger. Buying a mirror at a store will set you back hundreds of dollars, but I made my own for just a fraction of the cost.
I love the idea of hanging a large mirror in the entry way to reflect light. Update: There is no formal entry way in this house, but I will be placing our mirror on the left wall of the cozy room which will bounce a lot of light into the entryway.