Using AWS SNS to send SMS directly to phone number

Implemented "server-side texting" today using Amazon SNS.  To get this working, I had to set up a new IAM policy which allows a particular IAM role to publish anything (allow sns:Publish on "*").  This was the key to enabling SNS messages to be published directly to a phone number instead of a topic.  Also learned that in the U.S. it's not possible to set a meaningful "sender ID" instead of a random code like "788-98".  Other countries allow automated SMS senders to specify a meaningful value like a company name.