Build Passport Stamps with Gowalla
The Gowalla app for the iPhone/iPad is a location-based service. Mobile experts have long been predicting a radical change in the way users surf the web, because using mobile devices with built-in GPS functionality enables a whole new level of relevance to come to the experience.
That is, when the web knows where you're located, it can tailor the content that appears on your screen to that data, such as showing you search results for Thai restaurants located within driving distance.
Gowalla encourages its users to earn prizes for checking in at various locations while also sharing their opinions and pictures with their friends or other users. A business can buy a custom Passport Stamp for its location as long as a year in advance, to coincide with special promotions.
The stamps, which cost between $200 and $2,500, offer businesses a cool incentive for users to visit their locations and use their mobile phones to check in.
However, Gowalla functionality isn't limited to the users of its app. A site designer can give users a way to check in to Gowalla by inserting a hyperlink to the feature they want their audience to use when checking in.
For example, if you want your site users to add you as a friend and check out places you think are cool, you would have on your site a link that looks like this:
<a href="gowalla://users/YOUR USERNAME">Add me as a friend on Gowalla to explore some of the places I love</a>
You can also link to items such as the user's Passport (to highlight the number of badges they have earned) or to the specific URL for the spot where you want them to check in.
These links cause the user's iPhone/iPad to launch the Gowalla app; if it isn't installed, the link simply fails to work.
The 3G version of the iPad has GPS functionality built in. The Wi-Fi-only version of the iPad can still deliver some location-aware data to these services, but it does so primarily by using WiFi triangulation through the Skyhook API, to track the location of the WiFi hotspots the iPad is using to access the web. More on the Skyhook API.