[nbd]

Nice idea. Here are a couple of thoughts:

- How about showing the beginning of the message in the tweet? Something like:

Hey @Recipient, someone sent you a secret message: "Start of the messa....", read the rest at ...

This could be optional when creating the message, or you could let the sender pick out a phrase or few words they want to be displayed publicly.

- Does the actual message being sent have to conform to Twitter's 140-character limit? It's a little unclear on your site. If so, maybe add a Javascript counter that counts down available characters as you type. If not, this is a nice feature of your service (send longer directed messages to Twitter members) that you might want to list.

- The quote you are using ("Secrets are made to be found out in time") is cool, but implies that the service isn't really so secret.