Samsung is selling a device called the Smartphone GamePad along with a partner Mobile Console app. The GamePad is an accessory aimed at the company's Galaxy line of smartphones and is all about "enhancing the gaming experience" for players by giving the more familiar games console-like controls.
The controller attaches to Galaxy phones between 4-inches and 6.3-inches in size (covering most of the Galaxy range from small phones up to the big Note). The connection is facilitated by NFC for compatible devices, but is always over Bluetooth for actual gaming. The system also allows echoing of the phone's display to an HDTV via an HDMI cable or the AllShare Mirroring system. To promote games, the Mobile Console app is integrated with the GamePad's systems and acts as a storefront and launcher for compatible games, which Samsung asserts are "reasonably priced console-quality games without the expense of additional gaming systems."
It's an interesting move, and though we don't know pricing or full release dates yet (the initial release is in Europe), it seems like a device that may sell well over the holidays.
We do, of course, have to point out Samsung's familiar copying tricks. Apple's been looking at this market too, and recently enabled games controllers for iPhones and iPads--although it is pursuing the idea via approved third-party manufacturers.