Prepaid data plans have become increasingly popular, and they continue to get features that make them more attractive. That trend continues, as T-Mobile has confirmed rumors that its nationwide 4G plan will be available in prepaid form. This announcement makes T-Mobile the first U.S. carrier to offer an unlimited off-contract 4G data plan.

T-Mobile’s Unlimited Nationwide 4G Data plan will be available off-contract starting today for $70 per month. To help promote the new plan, T-Mobile will have a special offer going on the mid-range LG Optimus L9, which will be available off-contract for $199. The L9 includes a 4.5-inch qHD screen and a TI OMAP 4430 ARM processor under the hood. While it isn’t the most powerful device, it’s a pretty good deal for those who aren’t keen on signing a contract.

What say you guys? Who’s excited about an unlimited prepaid 4G plan?