Some bits I've liked:
- When I registered, it included instructions on how to associate my cell phone with my account (one of their usage models is that you can report who paid for dinner directly from the restaurant).
- Someone submitted a debt I owed them via my work address. The "you have been invited" email included a note saying "if you already have an account, here's how to merge this debt/email address into your existing account".
- The EFF loves their privacy policy.