We just cancelled our satellite on Sunday, so it hasn't been long but we've been watching TV over the internet occasionally for a few months now.
We purchased a cord online (couldn't find them in any stores) that connects our laptop to the TV. Basically it sets the TV up as a second monitor. It is very easy to do-- you really just plug it in and drag what you want to watch over onto the tv screen with your mouse.
We watch the instant play movies from Netflix this way and also watch some shows on hulu or directly from the station's website (disney, nbc, etc)