SneakyNote.com was written because I wanted an easy way to send passwords to clients.
Just wait until after the SneakyNote arrives safely before you actually change the password on the service.
A SneakyNote is a great way to exchange public keys for PGP or SSH because you can verify that your message wasn't modified.
No more snail-mail!
Need to give someone access to your bank account?
Split your account info into two or three parts and send each part in a SneakyNote, one after the other.
If your email account or your recipient's email account is hacked, then your old PGP messages become public when your private key is compromised.
Unlike email, SneakyNotes disappear. Send your PGP messages in a SneakyNote so the messages won't be around in the future.