What exactly does 4G mean? In short, it's next-generation wireless technology that promises data speeds at least two times faster than today's current 3G cellular networks. That means you should experience faster Web browsing and quicker downloads on a 4G smartphone. Here are the latest models available.

Samsung Galaxy S 4G smartphone (T-Mobile)

The good: The Samsung Galaxy has 4G connectivity, and a front-facing camera. Android 2.2 offers impressive data speeds.

The bad: No camera flash. The Galaxy S 4G has less internal memory than the Vibrant.

The bottom line: The Samsung Galaxy S 4G is a fantastic Android smartphone for T-Mobile customers.

HTC Inspire 4G smartphone (AT&T)

The good: The HTC Inspire 4G is affordably priced and boasts a large display. The Android 2.2 smartphone runs on AT&T's HSPA+ network.

The bad: The smartphone is rather large and heavy. Lacks a front-facing camera.

The bottom line: Though dual-core phones are on the way, the HTC Inspire 4G stands as one of AT&T's best Android devices.

HTC Evo Shift 4G smartphone (Sprint)

The good: The HTC Evo Shift 4G has a solid design with a comfortable physical keyboard. The Android 2.2 smartphone is 4G capable and can be used as a mobile

hot spot.

The bad: Lacks a front-facing camera and HDMI port.

The bottom line: For those who crave a physical keyboard, the HTC Evo Shift 4G is a solid choice with a more wallet-friendly price than its 4G competitors.