Many people have heard of Walkscore.com, and use it to tout the “Walk-ability” of a neighborhood. It's a bit of a fine line for agents to talk about this. “Walking distance” to or from a property is prohibited in marketing materials by Federal Fair Housing Laws based on non-discrimination requirements about disability. But without being biased, people want to know how close homes are to major amenities. And this is one of the ways people express that. So agents use Walkscore.com to share the information because it is just a statistical reference, not a judgement of value.
What a lot of people don't realize is that there are some other great neighborhood statistics at the same site. You can find about crime rates, public transit options, and the “bike-ability” of a neighborhood, or even a specific address. I imagine this will expand to include even more information as Zillow continues to dominate the real estate web space. There is a site for ParkScores (ParkScores.org) but it just gives macro information about cities as a whole. They don't give specific neighborhood data, but do offer city maps that give you a good idea where parks are located and where there is a lack of them.
The trend is to be want to be closer to major amenities and home values reflect that. A recent article in Better Cities & Towns compares the increase in values in areas of less urban density, and more urban density. It's clear that inner-city home values are escalating faster rate than outlying locations. But outlying areas with close-by amenities doing pretty well too.