In addition to the US-VISIT procedure, which I already experienced, there will soon be a US-EXIT procedure. At least, some procedure to make sure foreigners actually left the country. I made up the “EXIT” part.

Since basically every foreigner gets fingerprinted and has hir face photographed upon entry, DHS knows who entered the country. But of course they also want to know who left the country. After all, you don't want all those non-dangerous (hey, they were allowed to enter and therefore aren't terrorists) people to overstay their welcome. So now all foreigners will have their fingerprints taken and facial picture taken at the airport of departure. There are different ways to do this, as explained in an article. All of them seem to have one flaw though: traveller's credentials are checked before boarding the plane. What is to stop someone from walking back? Are they going to put up 10 ft high gates to keep people from sneaking back behind the gate agent's back? I wonder.

As for my person travels, I expect it'll just add extra time to the check in procedure. It doesn't seem like there is a way to implement a system that can be used in advance either, so it's not like gate agents can make the best of the standard delay time (ever been on a plane that left on time, since 9/11?) by checking people in advance. Handing people a receipt that they can hand over at the gate doesn't sound secure to me. How easy would it be for a US citizen to exit and drop off a receipt, if nobody scans his prints? How many gate agents really read and check all the information on passports and green visa waiver stubs right now? Going by my experiences, I'd say only the really new ones do. Not a good system. [Source]