Watching TV on 20" iMac

Is there any way to watch cable TV on an iMac? What do I need to buy?

Easiest way is with a TV tuner, ex. elgato makes EyeTV. You will only be able to connect via s-video or composite to these external tuners. Choose s-video at all times over composite.

What exactly are s-video and composite? Sorry if thats a dumb question, I dont know an incredible amount about computers... And what are the pros and cons of using one of these tuners? Will the picture quality be good? Will it slow the computer down? I have a 20" iMac 2.16ghz 2 gig ram 256mb radeon x1600 vc if it matters...

If you have ever connected a VCR (probably used a composite cable) or DVD player (probably s-video cable) or satellite box (prob s-video or coax cable) to your TV then you have used them.

Have had a TV tuner on my PC's since about '97. If you want to watch TV on your computer there are no cons, not really. Just have to learn what you can and can't do while simultaneously recording TV to your hard drive.

First thing you have to decide is if you want a tuner that works with analog TV (ntsc, the old standard on it's way out in a few years now) or you want to be able to watch digital SD & HDTV (atsc) in order to choose the appropriate tuner.

You will not be able to get any external HD video into your computer except for over-the-air TV.

Thanks, you really cleared things up. So, the Elgato EyeTV Hybrid sounds like a good choice. From what I understand you just need that, and a cable that plugs into the cable jack in the wall. Correct me if I am wrong, though.

The Hybrid is the one I have. Currently is the only one they make for the US that will receive OTA (over-the-air) digital TV.

Then your cabling depends on what you want to do. If you've looked at the Hybrid, at the end of it you will connect a coax cable (the round one the cable company uses to bring their signal to your TV (or cable box). This could be either from an external antenna for OTA or from your cable box. If you connect your cable box, you would do the same as you do with your TV, set it to channel ? (3 probably) and continue to use the remote for the cable box. This connection will be the best picture wise.

My connections are:
Rooftop antenna via coax connected for OTA HDTV
The breakout cable that comes with the Hybrid connected to my satellite via s-video for the picture and RCA for the audio.
The s-video actually will give a fairly decent picture, not component quality, but pretty good.

Check back in a week or 2, have been primary one answering these questions it seems like, so I will make a more detailed post (with pictures for cabling) on connecting the EyeTV with OTA, cable, satellite, DVD, VCR and Xbox 360. Just do a search for EyeTV, will probably call it "EyeTV connections" or something like that.

Thanks man, your helping me a lot.