Soaring gasoline costs have prompted keen consumer interest in finding the locations of service stations that have the lowest prices per gallon. The problem is an interesting one from a geographic perspective. The key to saving money is to find the lowest cost source of gasoline that is located as close as possible to a person's normal driving rounds. This allows the consumer to maximize savings by minimizing the cost of driving extra distances to search for cheap gas.  Web maps have proliferated to fill in local knowledge of where gasoline is cheapest just-in-time for a fuel-up.

For example, "Hatetopay," a Gasbuddy.com user, reported low gas prices on Frankford Avenue in Northeast Philadelphia at 5:15 pm on June 13, 200. The image to the right is a jpeg of the map showing Hatetopay's report of $3.99/gallon gas, along with prices found by other users at two other nearby locations. Gasbuddy requires individuals who report gas prices to create a users account. Reports (and searches) can be entered through text messages and browsers of cell phones or other mobile devices, as well as online with computers. The data submitted by users is available to the entire public. The vast majority of users and site visitors are located in the U.S., followed by Canada. According to the site traffic monitor application called Alexa, the site reach of Gasbuddy has increased by 266% and traffic is up by over 34,000 page views during the past three months (as of June 14, 2008).

A careful look at the whole Philadelphia region shows that very few people are posting prices for stations located in Center City (it's the area between I-76 and I-95 on the map) despite its dense residential population. Many price posts are located in main line suburban enclaves and along corridors used by commuters to enter and leave the city. There is also a large cluster of price posts in New Jersey suburbs. But, as with Center City Philadelphia, central Camden shows no posts. Gasoline prices in New Jersey are a little lower than those in Philadelphia because of different taxation policies by the states of New Jersey and Pennsylvania. The price differences leads many Philadelphia residents to cross the Ben Franklin Bridge to fill their tanks with less expensive gas and perhaps shop in nearby malls and supermarkets. The toll to cross the bridge may be increased from $3.00 to $5.00, so the economies of scale for pursuing the cheapest gasoline in NJ could change for some consumers.  However, there may several factors interacting that contribute to the Philly-NJ gas optimization-crossing phenomenon. Cheap gas, better access to groceries, recent relocation of health services for women from Philadelphia to New Jersey suburbs, and less expensive alcoholic beverages are a few examples of border differences that drive our local consumer geographies.

It is clear that one of the impacts web 2.0 is having in the context of the current economic crisis is to connect consumers with better information - "insider" views in particular - about where best to spend money on goods and services. Lime.com and Yelp.com are two web 2.0 applications that are rising to fill the demand for user identified and rated shops. Lime's focus is on fostering what is referred to on its website as "ecoist" lifestyles. For instance, many of the establishments identified are ones sell locally produced food and goods. Yelp is focused on providing a forum for the exchange of opinions about all kinds of local services.

All three of these services operate on the same basic concept - to create communities of users who contribute and access information about what is located in a given setting. The goal of these sites is to increase value of purchases and to help users match their spending and consumption with lifestyle preferences as closely as possible.

We note that this trend is just one of the many that excludes those who do not have access to digital technologies or the skills to use them. Once an individual has mastered the interface of one of the map-user-reviewer systems we have described, the skills are applicable to other similar sites. Searching for new web 2.0 map tools is also quite easy for those who have strong search skills, since there are many portals that list and review web 2.0 applications. But a quick glance at what has been mapped on Lime's  Philadelphia section gives users the impression that only the pocket of Center City has high quality, locally grown, organic, and tasty food to offer. North Philadelphia and Camden have no posts at all.

Citizen cartographers are bringing a torrent of new information about places into cyberspace. Gasbuddy, Lime and Yelp are just a few of the examples of how digital exclusion - either through opting out or because of digital divide barriers - may foster perceptions about what is on the ground among the members of the cyber-communities they create. We cannot help but wonder what effects this will have on geographies on the ground as this trend grows. Originally posted 6/15/08.

Michele Masucci, Temple University
David Organ, Clark Atlanta University
Caroline Guigar, Temple University