World Radio Network www.wrn.org is a London based service has been going for over 10 years, and offers programmes mostly in English (originally only bia satellite to Europe and USA, but now more widely). Choose the N American service for streaming audio and you can listen to a wide variety of programmes from the external services (think BBC World Service, so a mix of news, touristy-type facts/ history, and events) of different countries.
www.radio-directory.fm is a mostly US/Canada index of radio services, where you can locate stations by State and Genre.
Many of the 'talk' stations that have 4-letter callsigns like KQED, WBUR, WHYY, WQED, are public radio services, funded by the public paying a membership fee (in return getting baseball caps, magazine subscriptions, coffee mugs, thermos flasks, and so on, depending on the level of gift... from time to time there will be heard "membership drives" where they use the normal news/weather/traffic slots to ask for cash... whilst not carrying adverts as such, some 'sponsors' will be named, presumably pumping in hundreds of thousands or millions of dollars).
USA "public radio" networks: www.npr.org (National Public Radio) and www.pri.org (Public Radio International). Both services (and mpr.org - Minnesota public radio) have a wide range of shows from news quiz ("Wait, Wait, Don't Tell Me") to phone-ins ("Talk of the Nation") to variety ("Whadd'ya Know" and "A Prairie Home Companion") plus documentaries ("American Routes", "This American Life") and interviews ("Fresh Air").
Unlike the BBC, where they don't know the concept of podcasts being made available forever, several US / Canadian stations /programmes have podcast /"listen again" libraries that cover 10 to 30 years of broadcasts.