This can barely even be described as an Ikea Hack, as essentially I just slapped a bit of something on the back board of a slightly disreputable Billy bookcase that a friend passed along to me.
took the back of the Billy off and taped a large map onto it, I
didn't even cut it to size, just folded the corners over and taped,
then tacked it back on with new nails. An alternative would be to print
out some images from google maps and mod podge them onto the backing.
This was what I went with in the end. I cut the fabric to a slightly larger size than the backing, then taped it into place with white duct tape. It has kind of a lush, sheeny look to it. I think it would look great with a larger pattern or even with wall paper instead of fabric.