The Nokia Lumia 710, one of the first phones in the U.S. to ship with Microsoft's well-received Windows Phone 7.5 software, may have just arrived on the scene, but already it's priced as low as they go.

Walmart is offering the Lumia 710 for free with a two-year T-Mobile contract. Over at T-Mobile, the phone sells for $50.

How does the Lumia 710 stack up against other popular free phones? We assembled a quick tech specs chart to compare Nokia's handset with the Apple iPhone 3GS and the Android-based HTC Inspire 4G.

As you'd expect, the 2.5-year old iPhone 3GS doesn't match up well in the features department. Its processor, RAM, and camera specs look particularly primeval when stacked against those of the brand-new Lumia 710 and newish Inspire 4G.

Specs don't tell the entire story, of course, but the chart below suggests that Apple needs to pick up its game in a hurry. Today's free phones (OK, "free" with a monthly plan that factors in the price of the phone) are getting more powerful and feature-packed by the minute.

The iPhone 3GS already looks long in the tooth. You can only imagine what impressive features its freebie competitors will offer in, say, another six months.