Something that Al Michaels mentioned made me ask something I’ve actually wondered about for awhile. When Fitzgerald scored his 2nd TD tonite, Michaels said that the video feed on the scoreboard showed Fitz at the 15 when he was actually crossing the ten. Those who bring mini TV sets (or cell phones with 'net feeds) would be in the best position to answer this, and it may differ depending on the sport and/or network in question.
I think the standard live TV delay is 7 seconds. It gives the director a fighting chance to switch cameras or beep something out. But I don’t know if sports has the same delay.
The delay on HDTV vs SDTV, and between Cable and Satellite varies, up to about 10 seconds. Whenever I’m at my dad’s house and one tv is tuned to Cablevision, and the other to DirecTV, those watching cable will start cheering and the people in the other room on DTV will wonder why…oh, THAT’s why!
This is a great question. I’ve often wondered how live “live” means. I assume it’s less than 10 seconds, but who knows?
There’s also a delay between cable and over-the-air. On my antenna TV I’m seeing things at least 8 seconds before my mother right across the hall, where she has cable. It made the game tonight very interesting. It’s also really annoying when we’re both watching Jeopardy. 
Not exactly what the OP is talking about, and I am not sure if all DVRs do it, mine does. I have a DVR on the living room TV, but not the TV in the kitchen. If both turned to the same channel there is atleast a 3 second delay between them. I assume it is because the DVR is recording the live feed and then displaying the recording.
-Otanx
I notice it more at my parents home as they always have a radio on in the kitchen. If it is relaying a sports event that is also on the tv, the radio broadcast is always a few seconds( no more than 10.) ahead of the tv version.
About 5 years ago I was living about half a mile from a football ground when there was a game being played there shown live on analogue TV. When there was a goal I’d mute the sound, and then I’d hear the actual roar of the crowd a second or so later, once the sound waves had had time to travel over. So the signal for analogue TV was going out as near as instantaneously as it could.
My parents enjoy watching the local college basketball team on TV while listening to it on the radio. The amount of delay varies, but my mom likes it best when the radio is just slightly ahead–enough so that the radio guy says “He shoots, and it’s good” and Mom looks up and sees the basket being made.
She finds it exceedingly annoying when the TV is ahead–which it sometimes has been.
During Cubs games on WGN radio, they advertise some sort of device for your radio called “Sports Synch.” It somehow lets you add & adjust a delay to the radio broadcast so it matches what’s on TV.
That would be awesome for NHL games that are only on VS. I hate Doc Emrick.
I can get two NBC stations over the air, and they often differ by a couple seconds.
I found software that was freeware for a PC that was supposed to be able to add an audio delay, but could never get it to work. Maybe there are more/better versions out there now.