I think more useful would be the ability to also send small, twitter-sized messages instead of just transactions via darksend. Imagine that you could combine a transaction with a message or something like that. Hash the characters together and send it like a transaction, and all of a sudden, you have a really well encrypted, anonymous message system that overlays on an existing network.
I REALLY like this idea! Plus you can already have someone's address (cut and paste works fine) in your address book with whatever name you like, then call it up anytime. But an encrypted message to be sure the person knows where the money came from is brilliant