The email messages coming in on the watch, however, are read-only. Answer them with your smart phone.The “I’m Watch” sells for $350 from an Italian company of the same name.

– Sony’s “SmartWatch,” appears to be a similar device, scheduled to come out in March; pricing not yet determined. It will communicate with an Android smartphone through the Bluetooth short range wireless system. It too lets you take calls, see email, or play music and games. Don’t dunk it in water, but it’s OK if it gets a little wet. The display is 1.3 inches and like the “I’m Watch,” it looks bulky on slender wrists.

You install the tiny camera using your license plate bolts, and use the Magellan Roadmate 9055 GPS device as your screen. At seven inches, it’s a smaller screen than the ones that come in many new cars but larger than most GPS screens. The Roadmate gets great reviews because of its favorites menu, lifetime traffic alerts, points of interest info and member assistance from Automobile Club (AAA).

We saw the camera advertised for $150 and the Roadmate GPS viewer for $257 at Amazon. That makes it a bit over $400 plus some handyman skills to set this up. Some wiring to the taillights is involved because you want the camera to start broadcasting what it sees as soon as you put the car in reverse.

• Contacts Plus is a $2 app that brings in birthday information from Facebook and other sites. It also lets you send files from your tablet to your computer, phone or other devices. Google “Barnes and Noble Contact Plus” for more info.
• The Facebook app (free) is a handy way to keep up to date on Facebook. “Friendcaster” does this as well and adds a few more features.
• Evernote has been around for many years and is a nice free note-taking app.

What we were more impressed with were its features. The Firebird X guitar tunes itself. It has Bluetooth pedals so wires don’t get in the way. It has onboard special effects to create a variety of tones. It can sound like an electric guitar or an acoustic guitar, for example. The battery lasts for two hours before it needs recharging, but can be swapped out for a fresh one in seconds. All this jazz is expensive; the Firebird X is $4000 at Amazon.

Another high-tech option is the $400 Fretlight from Fretlight.com. Lights tell you where to put your fingers as you play a song. We found it too difficult for us, but dedicated guitarists may enjoy it.

Road Mice from Four Door Media also come as Lamborghinis, Mercedes, Fords and others, The price range is $35 to $50. They’re compatible with PCs and Macs.

• IBM is working on computers and phones that respond to your thoughts. Think about calling someone and it happens.
• Also on that track are a number of companies promoting TVs that let you change the channel just by thinking about it.
• The “LightPad” is a device that connects to your smartphone and projects its display onto a 60-inch screen. It includes its own keyboard and an eleven inch rear-projection screen.
• “SunBrite TV” lets you watch your favorite shows in bright sunlight – like out in the yard or on your boat.
• The Novo 7 is a $99 Android tablet complete with the latest “Ice Cream Sandwich” operating system. It’s the cheapest we’ve heard about, if you don’t count the $100 LeapPad for children, which sold out this Christmas.

1992 Smart Phone

A reader sent us an item from Time Magazine, which otherwise we never get around to reading. It’s a history of tech gadgets, many of which will surprise you.

Way back in 1992, IBM introduced an $899 device called “Simon.” Simon was a touchscreen mobile phone, personal digital assistant, pager and fax machine, all in one. It had a calendar app, calculator, address book and world clock. You could use your finger or a stylus on the touchscreen. For the whole list, do a Google search on “All time 100 gadgets” or click here.

Bob notes that to this day we get pitched on “new” products he saw 30 years ago at a trade show. Thirty-five years ago, the “Xerox Star” personal computer had a touch pad, a mouse and an icon display nearly identical to what was later used on the Macintosh. Xerox executives dumped the “Star” because they said there was no market for a product like that.

Amazon’s new $199 “Kindle Fire” may surpass the phenomenal sales of Apple’s iPad.

In the first five days it has been available for pre-order, 250,000 were sold. Apple sold 300,000 iPads on opening day, but that included pre-orders and live sales. If Amazon continues like this, the Fire will probably burn past the iPad.

Should you get one? Unlike the iPad 2, the Fire doesn’t have a microphone or camera, but its simplified interface makes it easy to switch from movies to games to books to photos. And no matter how many downloads you have, Amazon will store them for free if they originally came from Amazon. They have 18 million items: movies, TV shows, songs, magazines and books. Ten thousand movies can be downloaded for free if you pay $79 a year for a “prime” membership; which also gives you free two-day shipping on other Amazon orders. We took the deal because of the free shipping.

By the way: We recently saw a comparative price chart in the October 1, 2011 issue of the Economist magazine and Amazon’s prices were lower than Walmart and almost all other large retailers. The exceptions were Costco and Dollar General. Interesting stuff.

– “Teardowns: Learn How Electronics Work by Taking Them Apart,” by Bryan Bergeron; $25. The title strikes right to the point here, and the author tells you how things work, from smoke alarms to electric guitars, and provides pictures of the insides. Once you know how something works, you can think about ways to improve it or even make it obsolete.

– “Teach Yourself Electricity and Electronics,” by Stan Gibilisco; $35. This is like a text book, with a quiz at the end of each chapter. It’s well done, and includes some useful algebraic formulas. Basic stuff you should know.

– “Robot Builder’s Bonanza, fourth edition.” By Gordon McComb; $30. Build your own electronic sensors, make a spider robot out of electric guitar strings.

– “Arduino, a Quick Start Guide,” by Mark Schmidt; $35 and “Programming and Customizing the PICAXE Microcontroller,” by David Lincoln; $50. Both these books teach the reader how to program the two most popular circuit boards for controlling electro-mechanical devices.

– “15 Dangerously Mad Projects for the Evil Genius,” by Simon Monk; $25. The latest in the long-running Evil Genius series. What intrigued us here was how to make a magnetic coil gun. Projectile velocity is dismal; work on it.

– “Make, #27,” a regular magazine published by O’Reilly Books, $15 per issue. Covers many subjects but this one features turning a Roomba carpet cleaner into a roving spy robot.

Last but far from least each issue of the monthly magazines Popular Science and Popular Mechanics have instructions for building electro-mechanical projects. These are not toys! Want to build your own electron microscope?