Most humans know more than one language (though many Americans are monoglots). Of course, even when one has learned another language, that ability can be lost with disuse. The Internet is an amazing resource for learning and polishing language skills—the BBC has an excellent section on languages; not only do they offer their news and audio in many languages, but they also have tutorials for several major languages.
One of my recent finds is comic strips in Spanish. For me, it’s an enjoyable way to use my Spanish on a daily basis. GoComics has several strips in Spanish, including Calvin and Hobbes, Cathy, and FoxTrot. One can add their web feeds to one’s feed reader to keep up with them on a daily basis.