Geode details at this stage remain sketchy, but here's the example used in the alert about the project: "With Geode, a user who is looking for restaurants while they are out of town will be able load up their favorite review site and find suggestions a couple blocks away and plot directions there."
Geotagging most commonly refers to photos with geographic data stored within the file, but there are plenty of other cases, too. Many Wikipedia entries have geographic information encoded, and YouTube users also can geotag their videos.
There also are plenty of cases in which Web sites have geographic information such as a business address that's not formally encoded as geographic data. The gradual arrival of the semantic Web, in which descriptive elements help computers understand the data on a Web site, could expand that significantly.
The quintessential tools that make the geographic Web useful today are online maps. Those applications are getting more useful as mobile phones--especially GPS-enabled mobile phones--incorporate their use.