This is the Blender Logo keychain I created for the 10th annual Blender Conference (10-2012).

You can see the presentation I gave on 3D printing here: http://www.youtube.com/watch?v=pbDybxjQXuc

If you want to support my work, or don't have a printer, you can buy a printed keychain here:
https://www.etsy.com/listing/112191408/blender-logo-keychain

Print both the inner and the outer parts, then use your thumb to force them together. They are a tight fit so don't be too gentle!

The outer ring has a single small dimple on the inside. You can stick a small screwdriver in there to use as a lever to loosen the part from a hot print plate.