Just for fun, I researched the locations of 1,000 solo/small firm Toronto law offices. As one could guess, they are hudled around 290 ‘hot spots’ and concentrated heavily in the downtown area. Here’s a link to te map, courtesy of BatchGeocode.com (which allows you to plot multiple locations on a single Yahoo! map).
Based on my quick observations, the largest concentration of these lawyers are located along Young St. and near courthouses (e.g. University Ave. and Dundas St. West, Warden Ave. and Eglinton Ave. East, Dufferin St. and Finch Ave. West, etc.).