Want to get smart? Maybe you just want to hear a great story. Listen to podcasts.

What’s a podcast? Wikipedia says "a podcast or generically netcast, is an episodic series of digital audio or video files which a user can download in order to listen to." Think radio shows you can listen to anytime, anywhere.

Like audio books, excellent podcasts are available on most any topic you can imagine and many you may not have. Most podcasts are free of cost. Podcast episodes can range from a few minutes to an hour or longer. The best podcasts regularly release new episodes.

For instance, a fresh episode of The Daily produced by The New York Times downloads automatically to my iPhone before I rise each day. I can listen to The Daily as I go about my morning routine, in the car, at work, while exercising at the Y or walking at Waveny Park. Public Radio International’s Marketplace and WNPR’s The Colin McEnroe Show are other daily favs.

Weekly podcasts of what I used to call "trade reading" keep me abreast of business and technology developments. This Week in Tech is a favorite. Tech News Weekly, MacBreak Weekly, Make Me Smart are also weekly go-to podcasts.

A current favorite is The Dropout, the serialized story of Elizabeth Holmes and the biotech startup-cum-swindle, Theranos, which for a time made Holmes the world’s youngest self-made billionaire — before the company imploded spectacularly. Produced by ABC News and Nightline with content from The Wall Street Journal and other sources. Riveting story. Excellently told. New episodes each Wednesday.

Among the thousands of other excellent podcasts these are a few to try:

TED Talks Daily (HD video version)
Planet Money from NPR
The New Yorker Radio Hour
Hidden Brain from NPR
The World Next Week from CFR
OnBeing with Krista Tippett
Freakonomics Radio
Studio 360 with Kurt Andersen from PRI

Look for podcasts on iTunes, Spotify, Stitcher and other providers for a world of audio and video content.

Ask your friends what podcasts they listen to. Tell us your favorites.