The robohash robot is great. Optionally print out an image of the robot next to the identicon?
Users could check that the identicon maps to the robot and robots are easier to remember than patterns.
The robots would be good branding for bitcoin. It looks like robohash is open source.
Well it does seem that mskwik did just prove robohash to be useless for our purposes.
Not completely, it would be extra hard to find a robot collision AND collide the first few chars.