Couch potatoes can get up - and take their shows with them

The small screen is redefined - downward, to about the size of a Post-it note - in smartphone apps that play television programs.

But if that makes you think you'll get frustrated watching CSI: Miami, Hawaii Five-O, or old MacGyver episodes in the airport lounge, you should think again.

At the park (at least in the shade), on a train, in the passenger seat of a car, or when you're hiding in the corner at a cocktail party, TV apps on the high-resolution touchscreens that now grace phones are surprisingly easy to watch.

The viewing selection is much wider if you pay for a subscription to, say, Netflix or Hulu, which have their own apps, or if you are a cable subscriber who gets HBO.

The brand-new HBO Go app from Home Box Office Inc. is free to download and extends your access to what it says are 1,400 HBO shows, along with "behind-the-scenes extras."

One app for watching free television on the iPhone is from CBS-owned TV.com. It has video clips and full episodes of Late Show With David Letterman, Blue Bloods, the CSI shows, 60 Minutes, and classic Perry Mason and Twilight Zone.

The app also plays webcasts from the CNET tech-news operation, and episodes of a Web show, Clark and Michael, about two nerds.

Al Jazeera, the Qatar-based news organization, streams its English-language programming live via a free iPhone app, Al Jazeera English Live, from Livestation Ltd., that also displays written news articles and social-media tie-ins. Livestation also has apps for CNBC and BBC World News.

A free app called i.TV, from a company by the same name, works as a television guide on Apple devices. Set it up for your location and TV provider - cable, satellite, or antenna - and away it goes, building a grid to display shows, times, and episode synopses. You can use the app to log in to your TiVo DVR and manage recordings. And, there's a feed of entertainment news.

A caveat to all this is that video apps are a huge drain on power.

My iPhone battery indicator dropped from about half-strength into the red zone within about an hour of testing TV apps. Be aware that you may need to plug in after an episode or two of Star Trek.