Here's an inexpensive decorating idea:
Get a poster frame (we had an unused one in the garage). Turn over the glossy paper that comes in it, and fingerpaint on the back of it (or on the back of any old poster). Let dry, then place back in the frame for a unique piece of art to decorate a large blank wall.
Gerrick entitled this one "Fire and Lava". We haven't decided where to hang it yet, but he had a great time making it.