There are some websites where you can watch NBC (or WNBC) live online for free, however you should check broadcasting laws before doing so. Currently the best options for watching NBC live is by going to:
www.tvchannelsfree.com/watch/3681/NBC.html or www.stream2watch.com and nowwatchtv.blogspot.com/2011/05/watch-nbc-2-live-stream-free
However, these sorts of websites come and go so your best option may well be to Google "Watch NBC online for free” and try some of the top options. A couple of websites which have been branded around in forums no longer work or have been shut down.
Even if you manage to find one, the problem with live streaming remains its quality. It is often in poor resolution and can be a bit jumpy to watch. Even with the fastest, newest computers it can be a bit erratic and not always work for seemingly no reason, which can be quite frustrating.
If none of these sites are working, you may have to watch it online afterwards on the official NBC site. Most programmes etc are shown on here afterwards - www.nbc.com/video/ Watching it this way means you do not need to worry if you are breaking the law and you will also be able to watch it in better quality.
Another option is to go to YouTube and find the match or programme afterwards for the highlights, although this is not obviously ideal. Finally, you could also try and hunt out a pub that will be showing the games and sip on a shandy or a coke for two hours so it doesn’t cost too much.