Similar to Twitter's Digits, which has been around for a while and seems quite popular. https://get.digits.com

This seems interesting. Do you know of any app currently using this. I would like to quickly try it out before the hassle of setting it up myself.

Its free up to 100K SMS per month. Can find any pricing detail from Facebook.

As great at this probably is, I don't think adding yet another dependency to facebook is a good thing.

I'm getting tired of services that only accept facebook users. Having a facebook login or any other facebook service requiring the user to be a facebook user is not bad in itself (and can be pretty useful), but it should _always_ have an alternative.

That's why I think projects like Dial2Verify Twilio are a great thing. They're still not perfect though, as some said here on HN.