On a recent trip to New York City, my family and I visited the amazing Museum of Television & Radio. The heart of the museum is its Library, a collection of 120,000 television and radio programs. The library is amazing. First, you search the museum's electronic card catalog of television programs. It is vast, including important news broadcasts, sitcoms, commercials, programs that never aired, and more. When you find the program that you want to see, you can "check it out" by clicking a button.

In a few minutes, you are called down to the screening room and directed to one of the viewing stations where you can watch the program that you selected. You can even pause, rewind, and fast-forward through it. (I watched the pilot of a short- lived Party Of Five spin-off, my wife watched an unaired episode of Undeclared, and my daughter watched a black-and-white Lucille Ball special.)

I am confident that in just a few years, you wont need to visit the Museum of Television & Radio to have access to such a vast array of history and popular culture in video form: it will all be available online.

TV shows are already available online today. Right this minute you can to go the iTunes Music Store (which is kind of a misnomer now, because it offers television shows, music videos, and even a handful of movies) and download episodes of Spongebob Squarepants, Law & Order, Desperate Housewives, and more than 50 other shows. The selection isn't limited to new shows: you can also download episodes of Adam 12, Schoolhouse Rock, Knight Rider, and other classics. (Some might argue that Knight Rider doesnt qualify as a classic, but you get the point.)

50-plus shows at iTunes, plus another small selection at Google Video, is of course only a drop in the bucket compared to the thousands of programs on hand at the MT&R in Manhattan. But this is only the start: computers are now fast enough, and broadband ubiquitous enough, that video will soon revolutionize the Internet. When that happens, youll be able to punch up any episode of almost any show.

You can enjoy the cusp of that revolution today by legally downloading dozens of shows -- as well as thousands of video-podcasts, "vlogs" (video blogs), indie films, and other videos. Although your favorite show from today or the past might not be available for download yet, youll certainly be able to find something good to watch online.