Hulu, which has been in beta for a while, is now available to the public.  Currently it only works for the USA, but even with that limit, the ability to watch streaming movies and TV over the net is rather nice; they’ve even got some HD content.  They’ve made it very similar to watching TV, as you can expect commercial interruptions during your viewing.  Give it a try, you may find that the service they offer is free enough for you to enjoy using it.
“Hulu’s ambitious and never-ending mission is to help you find and enjoy the world’s premium content when, where and how you want it. We hope to provide you with the web’s most comprehensive selection from more than 50 content providers including FOX, NBC, MGM, Sony Pictures Television, Warner Bros., Lionsgate, and more to deliver premium programming across all genres and formats, television shows, feature films, and clips. Watch full-length episodes of current primetime TV shows such as The Simpsons and The Office the morning after they air, classics like Miami Vice and Buffy the Vampire Slayer, and clips from Saturday Night Live, Nip/Tuck, and others. Hulu also offers full-length feature films like The Usual Suspects, Ice Age, Three Amigos!, and The Big Lebowski as well as clips from films such as Napoleon Dynamite, The 40 Year Old Virgin, Devil Wears Prada and many more. Hulu is free and ad-supported — available anytime in the U.S.”