Timeline Ultra M5 14-inch Ultrabook computer, by Acer Corp.

$779.99 at Amazon.com

There’s a lot to like about Ultrabooks, the lightweight super-thin laptops now offered by the major computer makers. But most of these little machines suffer from one big drawback: price, which has generally hovered around $900.

So it’s nice to see Acer deliver a snappy machine with plenty of features at a sub-$800 price. The Timeline Ultra M5is really stacked. It’s got a hefty Intel i5 processor along with 4 gigabytes of RAM memory. Instead of a high-priced solid-state drive, Acer keeps the cost low with a half-terabyte mechanical hard drive. But you do get 20 gigabytes of flash memory, which boots up the Windows 7 operating system in less than a minute. The Timeline’s got another welcome feature not found in most Ultrabooks: a DVD drive for watching movies and playing tunes.

It’s got a comfy keyboard that’s backlit for typing in the dark, and a decent-quality LCD screen. One minor annoyance is a built-in battery that can’t be swapped out for a fresh one. But the iPhone and iPad have taught us to live with that nuisance.

The Timeline isn’t the fastest, thinnest, or prettiest Ultrabook. But when it comes to value for money, it’s an excellent choice.

Liquid-Armor screen protector,
by Dynaflo Corp.

$19.95 at Amazon.com

So far, I’ve had pretty good luck protecting the screens on my digital devices from scratches. Those thin plastic screen protectors work pretty well. But I recently learned about another option: a spray-on coating that claims to use super-strong nanoparticles to defend against screen abrasion. So how could I resist?

Liquid-Armor comes in a little spray bottle — enough to coat about 50 screens, according to the box. You also get a soft reusable cloth for applying the stuff. Just clean off the screen, spray a little Liquid-Armor onto the cloth, and wipe it on. It takes about 10 minutes to dry and a day to reach full hardness. And because it’s a ­liquid, you can use it on all kinds of video screens: phones, tablets, desktop monitors, TV sets.

I didn’t want to scar my iPhone or Android phone for life, so I sprayed Liquid-Armor onto the screen of an old BlackBerry and later took a knife to it. I managed to carve one small scratch onto the screen, but it took some effort. Liquid-Armor fended off every casual attempt to carve up the glass. It’s surely strong enough to deal with most accidental injuries. According to the manufacturer, each application should last about six months.

For a quick, effective alternative to one-size-fits-all screen skins, Liquid-Armor is worth a look.

DriveScribe safe driving app,
from Drive Power LLC

Free for iPhone and Android phones

Here’s a handy, unobtrusive tool that encourages teens and adults alike to be a little more careful on the road.

You install the app and sign up as a DriveScribe member. Then run the app whenever you’re behind the wheel. DriveScribe can be set to block incoming calls and messages while you’re driving. It also uses the phone’s GPS and accelerometer to track your speed, while accessing a database that knows the speed limit for the road you’re on. You get gentle warnings to slow down when necessary. You also get reward points for safely completing a journey.

These points aren’t worth anything to users­ of the free service. But if you become a paid subscriber, at prices ranging from $3 to $10 a month, you can redeem the points for discounts and gift cards from companies like Nike and Amazon.com. In addition, DriveScribe users can share their point scores on a company website, in effect competing with their friends for the title of Safest­ Driver.

There are lots of apps that try to goad people into better driving habits, but its incentive system might make DriveScribe the most effective one yet.