For one if you choose to register it uses an openID account, which is usable throughout various other web sites bypassing that 500th login/password combo you were going to create again.
Another quirky item is the default icons for each user. They have implemented use of a gravatar which basically translates to a unique image per user based on their IP address. Heres an example:
I've been very impressed with the simplicity of design while maintaining a slick minimalistic feel. All in all I wish the best for this site and hope everyone gets a chance to check it out.