Is Twitter Worth $1 Billion?

This morning I loaded up Twitter.com and received an error message telling me that the site was not responding. Not the good way to start the day for a billion dollar company. How did I come up with the company being worth $1 billion? I didn’t, my friend Nate Westheimer did. Nate wrote a piece suggesting that a mobile payment system would be Twitter’s ticket to becoming a billion dollar company in a short period of time.