What Kevin is doing is trying to create an entire downtown in Lego bricks.
I have taken a different approach. By building in what is called "minifig" scale (about 1/48 scale - based on the height of the chubby little Lego people), I can show details such as the individual windows and doors. Unfortunately unless someone pays me and lets me use a space the size of a stadium (for free), I will not be able to build an entire downtown. Dispite this, I am hoping to build many of the significant structures of Detroit.
Since I started building about 3 years ago, I have built one large structure a year (plus several small to medium size buildings).
2005: The 28 story Fisher Building:
http://www.flickr.com/photos/decojim/398371952/
2006: The 37 story David Stott Building:
http://www.flickr.com/photos/decojim/324881171/
2007: The 47 story Penobscot Building (still under construction):
After I completed the Fisher Building model, I found out about the Michigan Lego Train Club (MichLUG.org) and I joined it. This gives me the opportunity to display my Lego buildings as part of a complete city.
This is a picture from a show MichLTC did on March 3-4, 2007 at the Rock Financial Center in Novi, Michigan (a Detroit suburb):
(the buiding in the right-center foreground is a scaled-down replica of New York's Flatiron building by another club member).