I’m not able to check the book at this time, so I hope this isn’t another case where I post something that was already listed in the bibliography…but I read this book back in grade school, and it’s an excellent example of how Sagas could play out, IMO. The crux of the story is an outlawry dispute resolved by a bowshot contest, and the Althing (as well as the general Icelandic legal system) plays a substantial role in the story. (There’s also a creepy-cool scene in a viking barrow. ^_^ )
http://www.amazon.com/Story-Viking-Living-History-Library/dp/1883937019