"It's crazy. Everyone in the world is here," Crowley says, taking shelter from the Barcelona rain in a VIP lounge here at Mobile World Congress. He sat down with FastCompany at the wireless industry's biggest trade-show to help us wade through the latest innovations in 3D, NFC, UI, LBS and ... EZ-Pass, the highway toll thing.

"I find this to be an awkward size," he says while handling this writer's loaner phone from HTC, a sizable 4.3-inch Inspire 4G. Crowley, who carries an iPhone, likes the idea of a more compact device with less UI, especially when those devices can share their data connections. "All these things that have GSM [wireless] in them now don't really need it," he says, referring to tablets. (Elsewhere on the show floor, startup device-maker Iota was showing off two-button 2G devices with no screen, a simple headphone jack, NFC, and Bluetooth. They're called "wearable mobile voice and text hubs" for Android devices.)

Waze is a mobile application for most major platforms that is meant to be used while you drive. As you travel along your route, Waze uses the GPS data from your car (and other Waze users' cars) to draw its own road map of the area, almost like a map Wiki. "If you can get a critical mass of people using something like this, you can map places that haven't been mapped before, like shopping malls," Crowley says. He says he's considered that Foursquare could be used to make maps of foot traffic but says wading through all that aggregate user data would be tough. "Maybe at some point we'll build parts of our data firehose into an API" for third-party developers to play with.

"I'm bullish on NFC," he says, "especially with the iPhone 5 coming out, if it really does have it." Despite the face that industry standards haven't been set, "it might just ... happen," he says, "if the OEMs just get this stuff out there." But today's NFC isn't ideal for Foursquare, because it requires you to bring your phone within a few inches of a reader device. Crowley says he'll be searching the show floor for longer-range near-field technologies that enable phones to talk to other phones over hundreds of feet. "Kind of like EZ-Pass," he says, referring to payment nodes on the Northeast highway toll system, "but without all the high power antennas." A technology like this would make it easier for people to check-in to large venues like stadiums without the need for a Bluetooth or NFC reader in every single aisle. (The Samsung Galaxy S2, at left, is one of several powerful new NFC-enabled handsets introduced here in Barcelona this week.)

"I really just want to see that one in person," Crowley says of the LG Optimus 3D, which is (as the name suggests) a 3D Android smartphone. It doesn't require glasses, but uses a technology called "switchable barrier," just like the Nintendo DS.

Crowley believes Twitter to be the wireless industry's golden child, and CEO Dick Costolo's prime-time keynote on the first day of MWC would suggest he's right. Crowley says Twitter charmed carriers by offering a service that got users to spend more on text messages and data. Now, it's getting even closer to the industry: The company announced this week that it would use a new IP routing technology to enable smartphones to access Twitter regardless of geographic location or which network users are on. This would make it an actual service on the cellular network, just like SMS. It also announced a partnership with a large carrier named Qtel that covers North Africa, the Middle East, and Asia and enables tweeting via SMS in those regions.

Crowley liked that Howard Stern recently live-tweeted his own movie Private Parts while watching it on TV. "I'm a big fan of social TV," says Crowley, who recently ditched his cable box in favor of Internet video sources: a Boxee Box, along with an iTV adapter and a QAM stream connected to a Mac Mini. (Just across the hall, Eric Schmidt spoke Tuesday about Google's next big initiative: creating TV-quality video ads (and TV-level revenues) on mobile phones and other Internet devices.)

Crowley believes Twitter has made carriers hungry for the next big social app, and he's here to sell the vision of Foursquare as a new industry darling. He and two colleagues are here in Barcelona to begin talks with carriers and OEMs about the prospect of pre-loading Foursquare on phones, or using the company's branding inside carrier advertisements. What's Crowley's elevator pitch? "We show them 3,400% growth in the last year. "It's snowballing all over the world." Crowley spoke here at MWC on Monday, where he announced Foursquare's usership had hit a record 6.5 million. Foursquare check-ins, which rely on a phone's text messages or a data connection, have hit 2 million per day. Even we can't resist getting in the game.