Mark Sullivan, Megan Geuss

Remember a couple weeks ago when we discussed Ivy Bridge CPUs running a lot hotter than Sandy Bridge CPUs when overclocked? Well Loyd Case found a site that did a little experimentation and solved the mystery. (Hint: it's the awful thermal compound Intel uses.)

We're joined by Facebook expert Mark Sullivan to talk about the impact of Facebook's IPO, which should happen today. I think we're all in agreement that the company is way overvaulued, and will start snapping up other companies when the big flood of money comes in. With any luck, they'll avoid Yahoo's object lesson in how not to spend money.

PCWorld has released a new ebook detailing the various tech amenities available to tech-using travelers in the nation's largest airports.

“If the product is free, you are the product.”

At first glance that little maxim might seem cryptic, but it’s an apt description of the nature of Facebook’s service, and a needed heads-up for anyone who uses it. Although Facebook is a free service, the social networking site acts as a mechanism for capturing highly personal user information--Facebook's real product. That's your information. You are the product.

Dedicated mobile hotspots have been around for a few years now, but they've gotten progressively easier to use. And with the advent of 4G service, they’ve become notably faster, capable of connecting to more devices, and just a lot more useful.

We decided to compare the latest and greatest mobile hotspots from the two national 4G LTE providers in the United States, AT&T and Verizon. We lined up Verizon’s new MiFi 4620L Jetpack LTE hotspot against AT&T’s Mobile Hotspot Elevate 4G (by Sierra Wireless) to see which one worked better.

At CTIA in New Orleans today Sprint announced a first-of-its-kind mobile hotspot, the Tri-Fi Hotspot, which contains a CDMA radio and both a Wi-MAX and an LTE 4G radio.

This is a tailor-fit solution for Sprint, which is in the middle of a big project to upgrade its 3G CDMA network, build a new LTE network and keep its existing Wi-MAX network in operation. Sprint says the upgraded CDMA and new LTE networks will launch this summer.

Click to view our full-page map with the testing results.In our April 16 article "3G and 4G Wireless Speed Showdown," we reported the results of our exclusive 13-city tests of the four national wireless services: AT&T, Sprint, T-Mobile, and Verizon. Our study is the largest and best-known independent test of wireless service in the United States.

Here, in Part Two of our story, we drill deeper into the massive amounts of data that we collected over six weeks in February and March of this year. Whereas the first article reported the 13-city average speeds of the carriers, in this story we detail the carriers' performance in each of the ten testing locations we visited in each city.

How to Use the Map: We tested wireless service in 13 cities, and in each city we tested in ten locations. The map below displays our test results for each location.

To zoom in on a city, use the navigation controls at the upper left of the map, or click repeatedly on or near the group of map pins.

The Internet is like a fancy Hollywood party with lots of swag: You can get tons of stuff for free, but not all of it is good. Still, some of the Web services, apps, and downloads out there are great, and don’t require you to pay a cent. Our 17th annual roundup of free stuff includes dozens of no-cost services, apps, and programs that are worth your time. To help you find the most valuable freebies, we’ve categorized them based on which types of people they’ll help most. Enjoy the free life!

(To read the related story about each category of free stuff, click the appropriate heading below, or use the contents box to the right. You can also consult our alphabetical list of all of the downloads, apps, and Web services described in our Best Free Stuff package.)

For more information about all of the items in our 2012 Best Free Stuff list, read our package of articles.

The Best Free Software, Mobile Apps, and Web Services of 2012

Any.DO Website | Download (Android) | Review

Illustration: I Love DustStaying in shape is a constant struggle, but a slew of apps out there can help you track your fitness.

If you’ve always regarded counting calories as too challenging, try a new app called The Eatery (available on iOS only), which lets you snap pictures of your food and rate the general healthfulness of the meal. You can post images, and ask friends who use The Eatery to comment on them. From your self-reported information, The Eatery gives you insight into where the traps are in your eating habits, and how healthy your diet was for the past week. Looking for a more-specific diet tracker? Calorific for iOS and Android gives you a food library to record your calories, and assigns foods a red, yellow, or green light depending on whether they’re likely to help or harm your health.

Illustration: I Love DustYou need a vacation, and trips are sometimes expensive. Fortunately, you can find lots of services to plan your vacation that won’t cost you a dime.

For starters, as you’re deciding how to reach your destination, use the BeFrugal Fly or Drive Calculator to estimate the cost and time required to complete your trip by airplane or by car, so you can determine which mode of transportation is better.