294 Personal Content Experience: Managing Digital Life in the Mobile Age is, attaching the note to a location so that other users can see it while in the vicinity. An example of an annotation application with global 9 coverage is Google Earth, which among other things allows creating annotations on any location. The basic version of Google Earth is not classifi ed as a location-based application, since it is not aware of its own current location. However, there are more advanced versions available, such as Google Earth Plus, which adds support for GPS devices. There is a slight difference between a POI and an annotation. Put briefl y, the purpose of a POI is to name a location, whereas an annota- tion describes the location. Furthermore, the annotation is in many cases not tied only to the location, but to other context information as well, such as time. In essence, there is usually a contains relation between a POI and an annotation. By applying simple annotations, applications, such as fi shing jour- nals that are able to record the location of a bite, can be developed. Many stand-alone GPS receivers allow such limited annotations as a simple extension to mere wayfi nding and route planning. A textual annotation attached to a location is a good start, and can be considered as personal content. However, as discussed in Chapter 3, the relations between content items are an essential element that brings the separate pieces together and gives them meaning. Therefore, it would be benefi cial to be able to store, along with the annotation, a picture taken of the proud fi sherman, or the text message sent to the friends who were not able to attend the trip. Not to speak of combin- ing the content related to the situation from all the participants. Most stand-alone devices do not allow such integration of information, nor connecting to external devices and synchronizing it. 7.2.4 Location as Metadata Not all location information can be seen as independent content. Often, location information is a part of the context – the current user context, or the fi le context at the time the fi le was created. Increasingly, many content-related applications allow storing location as a metadata item.10 9 http://earth.google.com/ 10 For the sake of academic discussion, one could argue that all location information is metadata – an annotation, for instance, is a textual or pictorial piece of content, and the creation location is its metadata. However, we wish to make this distinction, since a location-based annotation loses its meaning if the location information is omitted. The line between an “annotation” and “a piece of content with location metadata” is indistinct at best.