Since I've opened my SSH port to the world (for subversion reasons), I get a daily wave of taiwanese people trying to access my box. They're using random user names. So far, none has gotten in.. When I discovered it, this afternoon, I added a few things to my sshd config (lowering the auth attempts, disabling password authentication). I might just disable SSH again and move towards HTTP access.
Some resources:
A Cure for the Common SSH Login Attack
Muppet SSH brute-forcer
