This is just a small two piece shelf. Essentially there is an insert portion you attach to the wall then the main shelf portion which slides over that to form the shelf.

You can watch a video of the printed thing at http://youtu.be/6uThGvuYpoo

I made this using google sketchup, when exporting to stl I select millimeters, then have to resize by .1 in replicatorg . I don't know if that is just my setting or what, but I always have to do that.

The insert on the right in the sketchup file is the one that fits, I forgot to delete the other one.

I printed the the insert part at a 100%, and the shelf at 15% infill. You may want to increase the length of the insert rods, but if you aren't going to put anything heavy on it, it shouldn't be a problem.

I haven't added any screw holes yet, for the insert, and I'll probably change it a bit, as the rods should be spaced a bit more as well.

Possible uses, small bathroom shelves along mirror, for like shaving cream. Slight modification for external wall mounted hard drives. Speaker Shelves. Frangrance pot holder. If you print bigger, it could possible hold your router, cable modem. etc..