I posted this over on the Air Travel forum, but I figured it would be of interest here too, especially if you don't have Global Entry...
US CBP has rolled out Mobile Passport Control at ATL. You download the free app Mobile Passport from iTunes, answer the same questions as the paper declaration form, and then get a digital receipt that allows you to use the express lane.
Here's the link: www.mobilepassport.us
And the press release from CBP: cbp.gov/newsroom/national-media-release/2014…
US and Canadians are eligible. iPhone for now, Android coming soon.
KEY TIP: You must enter your last name and then your first and middle names EXACTLY as they are on your passport.
Let me know if it works for you! Thanks!