By placing a geotag on a Web page, website, or RSS feed, you provide information to your readers and to search engines about the geographical location of the site. It can also refer to the location that the page or photo is about. So if you wrote an article about the Grand Canyon in Arizona, you could tag it with a geotag indicating that.



How to Write Geotags

The easiest way to add geotags to a Web page is with meta tags. You create a ICBM meta tag that includes the latitude and longitude in the contents of the tag:



You can then add other meta tags that include the region, place name, and other elements (altitude, etc). These are named "geo.*" and the contents are the value for that tag. For example:







Another way you can tag your pages is to use the Geo microformat. There are only two properties in the Geo microformat: latitude and longitude. To add it to your pages, simply surround the latitude and longitude information in a span (or any other XHTML tag) with the title "latitude" or "longitude" as appropriate. It's also a good idea to surround the entire location with a div or span with the title "geo". For example:



It's easy to add geotags to your sites.

Who Can (or Should?) Use Geo tagging?

Before you dismiss geo tagging as a fad or something that only "other people" should do, you should consider what types of sites you build and how geo tagging can be used to enhance them.

Geo tagging Web pages is ideal for retail sites and tourism sites. Any website that has a physical storefront or location can benefit from geo tags. And if you get your sites tagged early, they are likely to rank higher in geo tagged search engines than your competitors who scoffed and didn't tag their sites.

Web pages with geo tags are already in use in a limited format on some search engines. Customers can come to the search engine, enter their location and find Web pages of sites that are near their current location. If your business is tagged, it's an easy way for customers to find your site. And now that more phones are coming equipped with GPS, they can get to your storefront even if all you provide are latitude and longitude.

But even more exciting are new sites that are coming online such as Fire Eagle. These are sites that track customer locations using cell phones and either GPS data or triangulation. If a customer of Fire Eagle has opted-in to receiving retail data, when they pass by a location that has been encoded with geo data, they can receive contacts directly to their cell phone. By geo tagging your retail or tourist website, you set it up to connect with the customers who are broadcasting their location.

Protect Your Privacy and Use Geotags

One of the biggest concerns about geo tagging is privacy. If you post the latitude and longitude of your house in your web log, someone who disagrees with your post could come and knock on your door. Or if you always write your web log from a coffee shop 3 miles away from your house, a thief might figure out you're not at home from your geo tags and rob your house.

The nice thing about geo tags is that you only need to be as specific as you feel comfortable with being. For example, the geo tags I listed above in the meta tags sample are for where I live. But they are for the city and around 100km radius around my location. I feel comfortable with revealing that level of accuracy regarding my location, as it could be nearly anywhere in the county. I wouldn't feel comfortable with providing an exact latitude and longitude of my house, but geo tags don't require that I do so.

As with many other privacy issues on the Web, I feel that the privacy concerns surrounding geo tagging can be easily mitigated if you, the customer, takes the time to think about what you do and don't feel comfortable with. The thing you should be aware of is that location data is being recorded about you without your knowing it in many cases. Your cell phone provides location data to the cell towers near it. When you send email, your ISP provides data about where the email was sent from and so on. Geo tagging gives you a little more control. And if you use a system like Fire Eagle, you'll be able to control who knows your location, how specific they can learn your location, and what they are allowed to do with that information.