I'm using it as a currency. Compared to PayPal it's heaven - there are no weird rules about to whom you can send money and when and what for, it's much easier to use (you don't have to spend weeks to confirm your account, wait for credit card bills, fill out a thousand forms, etc.) and transactions are free, even international ones. Another bonus is that all accounts are publicly visible, so before donating to someone you can check how they're doing and decide whether to donate or not.

P.S. Comparing it to banks... doesn't really make sense. It's like comparing the Internet not to a telephone, but to a telegraph. That's why I used PayPal.