to sign a contract, others make no such requirement. Aside from the price at the register, consumers must also weigh the monthly cost for data plans and how that affects the total cost of ownership (TCO) for each tablet.

For this exercise, we left out sales taxes on the devices themselves, as well as government charges and additional fees that may appear on monthly bills. We're talking raw numbers here. Here's a look at what you'll pay over the long haul.

AT&T

AT&T is not offering the Samsung Galaxy Pad with a contract. Its no-contract pricing rings up at a whopping $650. AT&T says that Tab buyers will receive a $50 coupon for Samsung's Media Hub, where they can download music, movies and television shows. That doesn't make the $650 price at the register any less painful.

AT&T is offering two data plans for the Tab, neither of which requires a contract. The first costs $15 per month and allows for up to 250MB of data. Users who exceed that amount will be charged overage fees. The second plan costs $25 per month and allows for up to 2GB of data.

Over the course of two years, the TCO ($650 + 24x$15) for the Galaxy Tab adds up to $1010 for the 250MB plan, or $1250 for the 2GB plan. (Keep in mind, however, that these data plans can be turned on and off at will.)

Pricing for the iPad is actually a bit more complicated. Users can purchase the iPad for $500 - $700 with no contract and no data plan access. That means the TCO ranges between $500 and $700 -- as long as you don't pay for Wi-Fi. Add in a 3G radio, and things change.

The cheapest iPad with a 3G radio costs $630 (just $20 less than the Tab). The data plans for the iPad are identical to the Tab's. So, the two-year TCO for the 3G iPad with the $15 data plan ranges from $990 to $1190, depending on which iPad you buy ($630 for 16GB, $730 for 32GB, or $830 for 64GB). For the $25 data plan, the TCO ranges between $1230 - $1430.