This is quite embarrassing - twice in one month I'm going to use the word "mashup" - which hasn't even made it into the Cambridge dictionary yet. But perhaps you'll forgive me once we reach the end of this item.
The idea of a "mashup" is that you combine two different data sources together in a new way. My example was using Popfly to take my Flickr photos and displaying them in a virtual book through a mashup. Other examples are taking geographic information (like your student postcodes) and plotting them onto a virtual mapping website.
This has taken a leap forward, with something called MapCruncher, which lets you import and combine existing paper maps with Virtual Earth. This is another one of the projects to come out of the labs of Microsoft Research, and has appeared as a beta that you can use. The programme lets you take an existing map, like a map of bus routes, tourist hotspots, or hiking paths, and import it into Virtual Earth. You import the map, whether in vector (PDF, WMF, EMF) or raster (JPG, PNG, TIFF, GIF, BMP) format, find 5-10 landmarks on both the imported and Virtual Earth maps, and then create a mashup for use on a web page, and image tiles to match up with the road and aerial images in Virtual Earth.
There are lots of examples on the MapCruncher website, some of which include mapping a university campus onto the Virtual Earth satellite imagery. Imagine, if you have a multi-site facility (and most do!), being able to plot building floor plans and facilities onto a satellite image, so that you can see them all in position, with the local facilities and roads. How useful would that be for planning purposes?
Or, how about in Archaeology, being able to plot dig sites, with very detailed imagery or diagrams, over the map or satellite picture of the area.
Take a look at the examples on the MapCruncher website, including a college campus map. If you want to understand the detail you can overlay, take a look at Jeremy's lunch!
(Now, am I forgiven for saying "mashup"?)