Vending machines have always been social. People crowd around and share their thoughts on the best way to steal drinks, how far you can shake the machine before it falls over and whether or not the Coca-Cola script is really an obscene image.

Pepsi recently created a vending machine that’s truly social, in the 21st century sense. It’s still a prototype, but their “Social Vending System” allows users to gift beverages around the country.

Here’s how it works:

If you think your friend Sally, who lives thousands of kilometres away, would appreciate a tasty carbonated beverage, you simply choose a drink, shove some coins in, then enter her name and cell number. Sally will receive a special text message with the details, or if you’re at a special camera machine, she’ll receive a personalized video message.

All Sally has to do now is enter the code in any participating machine and claim her free drink. Easy.

To make their vending machines even more social 2.0, Pepsi’s Social Vending lets users engage in “Random Acts of Refreshment.” Facebook and Twitter users befriend strangers all the time, so why not send a Mountain Dew to some random dude across the country? He’s probably thirsty. Or maybe he’s looking for love. I predict Social Vending will spawn a new breed of “how we met” stories and will soon have its own reality show entitled “Love at Thirst Site.”

Pepsi’s press release says customers can also send “a symbol of encouragement to a city that’s experienced some challenging weather, or a congratulatory beverage to a university that just won a championship.”

Those are some pretty weak examples, but you get the idea.

The Social Vending System isn’t tied in with Facebook or Twitter yet, but social media integration is set for Phase 2. People won’t be satisfied with having to physically go to a machine to send liquid goodies to their friends, so hopefully by the time the novelty of Phase I wears off, Phase 2 will be ready to go.

This seems like a fun idea, but it’ll have to go mobile to succeed. Aside from the fact that it’s too much effort to walk over to a vending machine and buy a drink you won’t ever taste, people barely have enough cash to buy one drink, let alone another for their friend. Ordering drinks via smartphone would solve this problem, because everyone knows cyber money flows faster than physical money.

Plus, how many people will actually redeem their free drinks? To me, Social Vending sounds like extra money in Pepsi’s pockets. Clever.

Pepsi’s prototype machine is being shown off at a trade show in Chicago this week, with the hopes of “testing the concept with key strategic partners later this year.” All of the reports I’ve read use “prototype” in the singular sense, but I’m seriously hoping they made two. The only thing lamer than showing off a single Social Vending machine is demonstrating the power of one telephone.