If you're in the market for a no-contract cell phone and you want unlimited data, your options aren't exactly legion. Today US Cellular announced one more, albeit with some big drawbacks in the small print. For a limited time, you can pick up a new no-contract phone and enjoy unlimited talk minutes, texting and data for a month. That's the same price as the carrier's current 1GB plan.

As with US Cellular's previous plans, "unlimited" only means "unlimited" in the very selective way that some carriers use the term. To put it bluntly, your service is unlimited for the first 500MB, then it's throttled down to 1X (2G) speeds. Here's the legalese from US Cellular's terms and conditions:

No Contract Unlimited Data Speed: Full applicable data speeds apply for the first 500MB of usage. Data speeds shall be slowed to 1x thereafter for the remainder of the billing cycle.

No Contract Data is only available on certain phones. Application charges may apply when accessing applications. Customer must have a positive account balance in order to purchase applications. Not all applications are available for purchase by No Contract Data customers. Not all phones support all applications. U.S. Cellular reserves the right to terminate your service if more than 200 MB of your data usage in any month is used in U.S. Cellular's non-licensed markets. See store for details or visit uscellular.com.

Compare that to the $70 "unlimited" plan at T-Mobile, which is truly unlimited in both data and speed. US Cellular's plan is more or less exactly like T-Mobile's $50 plan, which offers 500MB of full-speed data and throttles down afterwards. Sprint's unlimited options start at $80 for a single phone, but requires a contract or a full-price phone. US Cellular's new promotional plan only makes sense financially if you're in an area that has excellent USC 4G and poor T-Mobile or Sprint coverage... and with the former's smaller network, that's unlikely to say the least.

US Cellular is offering the Moto X ($300 after rebates), the Samsung Axiom ($130), the Kyocera Hydro XTRM ($130), and the ZTE Director ($50) with the new plan. The carrier is still offering the more expensive standard plans alongside the $50 unlimited option, so there's no telling how long the promotion will last.

Source: US Cellular