I've read that at any given time, Google is running hundreds of experiments with various search results. Sometimes you notice one of these experiments in the wild. It's interesting to analyze such an experiment and consider where Google might be headed with it's search results.
It's no secret that Google Places, or the Google 7-Pack, is integrated into many search results with local intent. A search for a key phrase such as "Chicago bankruptcy lawyer" is going to display the Google Places results, prominently at the top of the page. Google is also trying to better understand your geographic location even when a search is performed for a generic keyword such as "lawyer". I came across a method Google was testing the other day to deliver localized search results for "lawyer".
Here is a screenshot of what I saw when I searched for "lawyer". As you can see, right at the top of the result is a box which prompted me to enter my zip code if I was searching for local results:

Subsequently, I entered my zip code into the box and I now got a list of Google Places results for my area. In addition, the organic search results underneath the Google Places listings had changed. Localized results for the city of Chicago had replaced many of the previous results. Here is another screen shot of the results after submitting my zip code:

What Is This Telling Us?
I always like to think about search marketing from the standpoint of what Google wants. Rather than trying to "game" the system, consider what Google's intentions are and align your strategy accordingly. Google wants to deliver the best, most accurate results to its users. In the case of someone looking for an attorney, Google wants to provide results that are localized and accurate to the searchers query.
The biggest takeaway from this is the tremendous opportunity available for firms to build an established web presence in their local community. Optimizing your site for your local area will result in targeted traffic and it appears as if Google is trying to siphon traffic from some of the most searched for, generic terms, such as "lawyer", to local businesses too.