If your cable provider has made a deal with ESPN you can access ESPN live from your iPhone, iPad, computers, and Android devices. And the quality of the picture is great! This is very similar to the HBOGO app that allows you to get HBO wherever you are. This is progress!
It is not available on for all cable subscribers, but it is available to you if you have Comcast, Verizon FIOS, and many other companies.
Here's the description of the service from ESPN:
Get 24/7 live streaming access to your favorite ESPN networks on your smartphone and tablet via the WatchESPN App* or online at WatchESPN.com
Catch all the action from ESPN, ESPN2, ESPN3, ESPNU, ESPN Buzzer Beater, and ESPN Goal Line including college football, college basketball, Monday Night Football, international soccer, SportsCenter, PTI, and much more.
Here's the link to the app in iTunes.
Here's the link to the Android apps.
Here's a video from ESPN outlining the app and how it works. And the picture quality is as good as you see in this video.