TightWind is written by Kyle Baxter. Stay Hungry. Stay Foolish.

John Gruber had this to say about news that iOS 5 will be able to upload photos directly to Twitter:

So close to the bigger story, but yet so far. Imagine what else the system could provide if your Twitter account was a system-level service.

(Looks like he pulled back the first sentence, but the full thing came through in Reeder for me. Sounds like Gruber’s holding back a little news.)

So just to speculate along Gruber’s hint, Twitter usernames could be tied to contacts, and we could send direct messages rather than SMSes. So, when you send a message to someone from the SMS app, iOS checks if that person has a username tied to their contact and they are following you on Twitter (so you can send them direct messages), and if so, sends a DM instead of an SMS. Nice way to save on SMS plans.