Blaubo Design are a design company using custom tiles with the Google Maps API to create an interactive zoomable image map. The company have stitched together shots of a number of their website designs and created map tiles from the image.
Using the Google Maps interface to browse the designs enables the user to centre on any design and zoom in to view details. Blaubo Design have also used map markers for each design. This means the user is able to click on the relevant marker and open an information window with a link to the actual web page shown.
The only improvement I would suggest is to create transparant clickable polygon areas over the titles, which are on the top of each design. At the moment they look like links but aren't. Creating clickable polygons could turn them into links.