as far as I know there is no other place to get this. I was not able to find it (or any of the other keys I've designed) anywhere else and that is why I made them.
You can order this one here from Shapeways if your house key is the SC1/66 type used by Kwikset, Defiant, etc. and then have it cut at your local hardware store.
I have two other blank types as well.
KW11/97 - http://shpws.me/GVa9
This one is also used by Kwikset and others but is a longer key blank for locks with 6 pins instead of 5.
SC1/68 - http://shpws.me/GMPQ
This one is used for Schlage locks.
If you are not sure what type of key you have, you should be able to check for the manufacture name on the key or lock. The key may also be stamped with one of the markers I've mentioned above (KW1, 66, 68, etc). Otherwise you can have your hardware store check the key.