Moxie, downloaded this and finished it on a business trip to Germany over the last couple of days.
Have to say that I thought it was excellent. I do have a low boredom threshold with free stuff but Concrete Underground absolutely gripped me from the start. Great characters, gripping story and all told in really good writing. As a bonus I'm going to look up some of the soundtrack mentioned as well (not as daft as it sounds, I got into Warren Zevon through the fact that all of Carl Hiaasen's cool characters listen to him).
Thanks Moxie, keep up the good work