When you buy a cell phone in the United States, the carrier normally subsidizes it as long as you sign up for a two-year service contract. AT&T announced Thursday it was bringing that business model to laptops with embedded 3G modems.

The telecommunications company inked a deal with Lenovo to offer up to $150 off the full range of ThinkPad notebooks when a customer signs up for a two-year mobile data plan. The companies are eyeing the enterprise market with this agreement, and think the upfront IT savings will make it attractive for businesses.

To get the discount, users will have to sign up for the AT&T's DataConnect service, which costs about $60 a month. Eligible Lenovo laptops will have a built-in Ericsson modem that's capable of receiving download speeds between 700 Kbps and 1.7 Mbps, and typical uplink speeds between 500 Kbps and 1.2 Mbps.

"We have seen mobile data consumption quadruple every year for the past three years," said Michael Woodward, AT&T's VP of mobility business marketing, in a statement. "Customers recognize the benefits of enhanced connectivity on their notebook computers, and this increase in consumption reflects that."

The offer is available now and will include the three ThinkPad SL notebooks, as well as all notebooks in Lenovo's T and X series.

With workers becoming increasingly mobile, the deal may be attractive to businesses with multiple road warriors. But enterprises should be aware that the embedded modems will only work with AT&T's 3G service.

The company does offer 30 days of free DataConnect service, and then the two-year contract kicks in. If users want to cancel the 3G service, there's a $175 early termination fee that decreases $5 for each full month of service.