Mashups are an exciting genre of interactive Web applications that draw upon content retrieved from external data sources to create entirely new and innovative services. They are a hallmark of the second generation of Web applications informally known as Web 2.0.
Taken directly from the IBM website,
A good insight as to what makes a mashup is to look at the etymology of the term: it was borrowed from the pop music scene, where a mashup is a new song that is mixed from the vocal and instrumental tracks from two different source songs (usually belonging to different genres). Like these "bastard pop" songs, a mashup is an unusual or innovative composition of content (often from unrelated data sources), made for human (rather than computerized) consumption.
Of all the different kinds of Mashups out there, the one that I seem to get is the Mapping mashup. There are several different easy applications for this kind of mashup. Obviously the most famous one is the chicagocrime.org which maps crime data with google maps to create a visual representation of crime hotspots in the city.
Another business application to something like this would be to display home locations of willing employees on the corporate Intranet. This would make social networking in a corporate setting more achievable and more personal. This can tie directly into my other post on this blog that talks about the socialization of the corporate Intranet.
If we dont want to be radical enough to show where people live in a corporate setting, we can at least show ion their office location on an interactive google map. Take a look at this sort of mashup application. http://www.laudontech.com/officeplans/test5.php5
In closing, I would like to say, the new Web 2.0 is going to revolutionize the way we aggregate and present data.